JP4405300B2 - Polyester film-coated metal plate and polyester film-coated metal can excellent in dent resistance - Google Patents

Description

The present invention relates to a polyester film-coated metal plate and a polyester film-coated metal can obtained by molding a polyester film-coated metal plate. More specifically, the present invention relates to a polyester film-coated metal plate having excellent canability (for example, drawing and ironing workability). Particularly, polyester having high productivity and good yield due to its excellent high-speed canability. The present invention relates to a film-coated metal plate.
In addition, after filling and sealing the contents of the can, for example, even if the can is subjected to blow or impact such as dropping, the inner film is unlikely to be destroyed or damaged, so it has dent resistance. Since it has excellent characteristics, it is excellent in the preservation of contents.

  Conventionally, metal cans and containers made of steel or aluminum are roughly classified into three-piece cans and two-piece cans according to their shapes. Three-piece cans are called three-piece cans because they consist of a ground cover, a can body, and a canopy, and steel making methods are currently mainly used for seam welding and bonding, so inexpensive steel is used. On the other hand, the two-piece can is an integrated body and can body, and because it consists of a canopy, it is also called a two-piece can or a seamless can because there is no joint in the can body. Canned by drawing and ironing, steel and aluminum are used.

In the case of a metal can, the inner surface is painted from the viewpoint of preventing corrosion by the contents, while the outer surface is painted and printed from the viewpoint of presenting the contents and presenting the trademark design. Various types of thermosetting paints such as epoxy and phenolic used in such coatings are widely used because they coat and dry a resin dissolved or dispersed in an organic solvent. ing. However, such a thermosetting resin coating method has a drawback in that it often causes various problems such as a long drying time, a decrease in productivity, and environmental pollution caused by a large amount of organic solvent.
In order to solve these various problems, laminate cans in which a thermoplastic resin film is laminated have been developed and put on the market in recent years, and a technique for coating a resin film on a metal plate is disclosed in, for example, Japanese Patent Laid-Open No. 2-70430 ( JP-A-4-224936 (Patent Document 2) and JP-A-6-320669 (Patent Document 3).

However, in the disclosed technology, when applied as a film for the inner surface of the can, the can wall portion represented by the formula (1) has a high degree of processing (also referred to as a plate thickness reduction rate) for drawing and ironing processing. There is no film to endure, and if the ironing process with a high degree of processing is performed, the film does not follow the molding, so that the microcrack is likely to enter the film in the can body part, and in the case of severe, the film may be broken.
Furthermore, for example, when high-speed molding of 60 cans / minute or more is performed, the film on the inner surface side of the can adheres to the molding punch, and the problem that the punch is difficult to come off is likely to occur. It also has the disadvantage of being inferior.
Degree of processing (%) = ((original plate thickness−can wall thickness) / original plate thickness) × 100 (1)

  Also, after the can body is filled and sealed, if the can body is hit or impacted by dropping, etc., the metal material will not only be deformed at that part, but at the same time the impact, impact and metal material There may be a situation where a film or coating film covered by deformation is cracked or peeled off. Such cracked or peeled parts of the film or coating film become the starting point of corrosion of the can body metal, and depending on the contents, the form of metal corrosion becomes pitting corrosion and the can body becomes a perforated can. There is a case.

  Therefore, it is important that the coating film and film are resistant to cracking or peeling even when the can body is hit or impacted by dropping or the like. However, in the case of crystalline polyester, the dent resistance is significantly reduced by hot water treatment such as retort sterilization treatment and hot water treatment such as pastro sterilization treatment. There were restrictions.

  A technique for improving the dent resistance of a resin film is disclosed in, for example, JP-A-9-323379 (Patent Document 4). This technique includes (A) a crystalline polyester mainly composed of ethylene terephthalate and (B) Polybutylene terephthalate or a blend of crystalline polyesters mainly composed of polybutylene terephthalate units, a technology that limits the transesterification rate in the blend, but is basically a highly crystalline polyester Dent resistance after hot water treatment such as hot water treatment such as retort sterilization treatment and pastro sterilization treatment as described above, because it is difficult to control the transesterification rate in the blended product, etc. However, this technology cannot be said to be sufficient.

Further, in Japanese Patent Application Laid-Open No. 7-2241 (Patent Document 5), the surface layer is made of polyester or copolyester mainly composed of ethylene terephthalate, and the polyester or copolyester mainly composed of butylene terephthalate is formed on the side in contact with the metal. It has a multilayer structure consisting essentially of polyester or copolyester mainly composed of ethylene terephthalate, and the birefringence of the surface film on the bottom and top of the can is limited to 0.04 to 0.18 in the can state. Technology has been proposed.
However, in this technology, the surface film on the bottom of the can that has not been processed also has a birefringence, so the film is oriented and crystallized at the stage of the laminate material used for molding processing, and the dent resistance is good. However, it was not suitable for drawing and ironing, especially for drawing and ironing at high speed and high working degree.

  Japanese Patent Laid-Open No. 6-255022 (Patent Document 6) discloses means for imparting impact workability at low temperatures by a method of coating a metal plate with a resin layer blended with a polycarbonate resin and a polyester resin; No. 226915 (Patent Document 7) discloses means for imparting impact workability by a method of coating a metal plate with a two-layer film composed of a polycarbonate resin layer and a polyester resin layer. Due to the environmental hormone problem that has become a problem, it is difficult to put it into practical use.

  Further, a polyester-coated laminate having good dent resistance is disclosed in Japanese Patent Application Laid-Open No. 10-119183 (Patent Document 8). This technique is (I): polyethylene terephthalate segment, (II): butylene. Polyester segment derived from glycol and aromatic dibasic acid, (III): Polyester segment derived from butylene glycol and aliphatic dibasic acid (I): (II): (III) = 10-70 It is a laminated body made of polyester containing from 12 to 81: 3 to 54% by mass and further containing from 0.01 to 1.5% by mass of a hindered phenol-based antioxidant.

  However, when trying to obtain a metal can by drawing and ironing the laminated body at a high speed of, for example, 80 cans / minute, the releasability from the processing punch or die is poor, and the film is broken or galling occurs. Was likely to occur and was not satisfactory as a polyester-coated laminate. Therefore, at present, there are not many that can be drawn and ironed at high speed and with high processing, and the resulting can body has excellent dent resistance, and it is a reality that the appearance of such a can body is desired. .

JP-A-2-70430 JP-A-4-224936 JP-A-6-320669 JP-A-9-323379 Japanese Patent Laid-Open No. 7-2241 JP-A-6-255022 JP-A-6-226915 Japanese Patent Laid-Open No. 10-119183

  The polyester film-coated metal sheet of the present invention has a high speed (for example, 60 cans / minute or more) and a high degree of processing (for example, the plate thickness reduction rate of the can body described above), especially in can manufacturing by drawing and ironing. A polyester film-covered metal plate having excellent canability at 25% or more and a local maximum plate thickness reduction rate of the can body portion of 50% or more is provided. In addition, the can body of the present invention has excellent corrosion resistance.For example, even if the can body after filling and sealing the contents is hit or impacted by dropping or the like, damage such as cracking or peeling occurs on the inner film of the can. Since it has a good dent resistance which is difficult, it can provide a can body excellent in storage stability of contents.

  In particular, the above-mentioned characteristics such as good dent resistance are good even after hot water treatment such as retort sterilization treatment or pastro sterilization treatment applied after filling and sealing depending on the contents. Therefore, the present invention provides an excellent polyester resin film-coated metal can that can cope with various contents.

In order to achieve the above object, the polyester film-coated metal plate of the present invention is a polyester film-coated metal plate in which a polyester film (F) is coated on a surface corresponding to at least the inner surface side of the metal plate, The polyester film (F) is a two-layer film having a total thickness of 10 to 40 μm consisting of a polyester film layer (A layer) having a thickness of 5 to 20 μm and a polyester film layer (B layer) having a thickness of 5 to 25 μm. The metal plate is coated with a polyester film layer (B layer) in contact with the metal plate, and the polyester film layer (A layer) has a melting point (A-Tm) of 235 ° C. or higher and an intrinsic viscosity (A-IV). 0.60 or more, heat of crystal fusion (A-Hm) and / or cold crystallization heat (A-Hc) of 25-50 J / g, glass transition temperature (A-Tg) of 65 ° C. or more, 0.5 to 1.0 wt% of lubricant average particle diameter size is 0.4~2μm and 0.01 to 3 parts by weight of the heat stabilizer and / or antioxidant relative to 100 parts by mass of the polyester resin The base resin is a polyester resin (A) that is contained in the range of 0.1 to 10 parts by mass of rubber elastic resin (R) particles having an equivalent sphere equivalent diameter of 2000 nm or less with respect to 100 parts by mass of the polyester resin (A). Is a film layer made of a mixed polyester resin containing 0.01 to 3 parts by mass of a vinyl polymer (V) having a polar group, and the polyester film layer (B layer) has a melting point (B-Tm) of 220 ° C. or higher. Viscosity (B-IV) is 0.55 or more, heat of crystal fusion (B-Hm) and / or cold crystallization heat (B-Hc) is 20 to 45 J / g, glass transition temperature (B-Tg) is 45 ° C. As mentioned above, heat stabilizer and / or Is based on a polyester resin (B) containing an antioxidant in a range of 0.01 to 3 parts by mass with respect to 100 parts by mass of the polyester resin, and an equivalent spherical equivalent diameter for 100 parts by mass of the polyester resin (B). It is a film layer made of a mixed polyester resin containing 5 to 40 parts by mass of fine particles of rubber elastic resin (R) of 2000 nm or less and 1 to 10 parts by mass of a vinyl polymer (V) having a polar group. And a polyester film-coated metal plate.

More specifically, the rubber elastic resin (R) is polyethylene and / or ethylene-butene copolymer.
In order to achieve the above object, the metal can of the present invention is a metal can obtained from the above polyester film-coated metal plate by molding, particularly drawing and ironing, on the inner surface side of the can body. A polyester film-coated metal can in which the density of the coated polyester film (F) is 1.360 g / cm ³ or less.

  As described above, in the polyester film-covered metal plate of the present invention, the polyester film (F) is coated on the metal plate surface corresponding to at least the inner surface side of the can, and the polyester film (F) has a thickness of 5 A film having a total thickness of 10 to 40 μm composed of a polyester film layer (A layer) having a thickness of ˜20 μm and a polyester film layer (B layer) having a thickness of 5 to 25 μm. The polyester film layer (A layer) has a melting point (A-Tm) of 235 ° C. or more, an intrinsic viscosity (A-IV) of 0.60 or more, and a heat of crystal fusion. (A-Hm) and / or a cold crystallization heat (A-Hc) of 25-50 J / g, a glass transition temperature (A-Tg) of 65 ° C. or higher, and an average particle size of 0.4-2 μm. The polyester resin (A) containing 5-1.0% by mass and a heat stabilizer and / or an antioxidant is a basic resin, and the equivalent spherical equivalent diameter is 2000 nm with respect to 100 parts by mass of the polyester resin (A). A film layer comprising a mixed polyester resin containing 0.1 to 10 parts by mass of the following rubber elastic resin (R) fine particles and 0.01 to 3 parts by mass of a vinyl polymer (V) having a polar group. Layer (B layer) has a melting point (B-Tm) of 220 ° C. or higher, intrinsic viscosity (B-IV) of 0.55 or higher, heat of crystal fusion (B-Hm) and / or cold crystallization heat (B-Hc) 20 to 45 J / g, glass transition temperature (B-Tg) is 45 ° C. or higher, polyester resin (B) containing a thermal stabilizer and / or antioxidant is a basic resin, and polyester resin (B) 100 mass Against the department A film layer made of a mixed polyester resin containing 5 to 40 parts by mass of fine particles of rubber elastic resin (R) having an equivalent sphere equivalent diameter of 2000 nm or less and 1 to 10 parts by mass of a vinyl polymer (V) having a polar group; By using a polyester film-coated metal plate characterized by being, it has the advantage of being excellent in can-making performance (for example, drawing and ironing workability), especially in high-speed and high workability. Have.

In addition, the can obtained by carrying out the present invention has a soundness as a can body because, for example, even if high-speed and high-working drawing and ironing processes are performed, it is difficult for a scratch on the inner film generated during molding to enter. It has the advantage that it can be secured.
The polyester film-coated metal can of the present invention is a metal can obtained by molding from the polyester film-coated metal plate, and the density of the polyester film (F) coated on the inner surface side of the can is 1.360 g. / Cm ³ or less polyester film-coated metal cans, microcracking of the film that occurs when the can filled with the contents is dropped, especially hot water treatment such as retort sterilization treatment and pastro It has the advantage of having excellent dent resistance such as being hardly generated even after being subjected to hot water treatment such as sterilization treatment.

  The polyester film-coated metal plate which is the first invention in the present invention will be described. First, the polyester film (F) applied in the present invention will be described. In the present invention, the polyester film (F) coated on the metal plate surface corresponding to at least the inner surface side of the can is a film having a two-layer structure comprising a polyester film layer (A layer) and a polyester film layer (B layer). In this case, a crystalline polyester resin is used as the basic resin, and the polyester film layer (B layer) is covered with the metal plate.

  In the present invention, the polyester film layer (A layer) has 0.1 to 10 parts by mass of polar particles of rubber elastic resin (R) having an equivalent sphere equivalent diameter of 2000 nm or less with respect to 100 parts by mass of the polyester resin (A). The vinyl polymer (V) having a group contains 0.01 to 3 parts by mass with respect to 100 parts by mass of the polyester resin (A), and the polyester film layer (B layer) is 100 parts by mass of the polyester resin (B). 5 to 40 parts by mass of fine particles of rubber elastic resin (R) having an equivalent sphere equivalent diameter of 2000 nm or less and 1 to 10 parts by mass of the vinyl polymer (V) having a polar group with respect to 100 parts by mass of the polyester resin (B) Contains.

  The film layers of the polyester film layer (A layer) and the polyester film layer (B layer) interact with each other with respect to moldability and dent resistance, but basically share roles for achieving the object of the present invention. The polyester film layer (A layer) is mainly responsible for securing canability at high speed and high workability, and the polyester film layer (B layer) containing the rubber elastic resin (R) is mainly used. It is responsible for ensuring dent resistance. In order to greatly improve the dent resistance of the film, it is essential to be able to absorb the energy of impact and impact. The elastic resin (R) is contained in the basic polyester resin, and the energy of impact and impact is reduced. The action to absorb is given. Of these resins having rubber elasticity, a resin having a glass transition temperature (Tg) of 10 ° C. or less is most suitable.

This is because, for example, carbonated drinks and beer are naturally stored at low temperatures, and therefore must have an action of absorbing energy of impact and impact even at such low temperatures.
In this sense, a resin having a glass transition temperature (Tg) of 10 ° C. or lower, more preferably a resin having a glass transition temperature (Tg) of 4 ° C. or lower, is good for ensuring dent resistance.
Suitable resins for the rubber elastic resin (R) are polyethylene and ethylene-butene copolymers, and one or two of these resins can be applied.

When polyethylene is applied, fine particles of polyethylene resin having a density in the range of 0.90 to 0.96 g / cm ³ are particularly optimal.
The reason for this is that when the density is less than 0.90 g / cm ³ , it depends on the amount to be contained in the polyester resin. In some cases, film residue may occur at the shear edge called the film hair. If this film residue is detached at the time of molding a cup and adheres to a cup or a mold, it may cause a quality defect or a molding defect of the can body and cause a serious problem.

In addition, since the film becomes hard when the density exceeds 0.96 g / cm ³ , there is no problem with the above-described film, but the ability to absorb impact energy is reduced, and the dent resistance improvement effect that is the object of the present invention is as follows. Becomes small and is not preferable.
Rubber elastic resins such as polyethylene and ethylene-butene copolymers are incompatible with polyester resins, and therefore exist as dispersions in polyester resins.

Furthermore, in the present invention, the resin such as polyethylene or ethylene-butene copolymer present as a dispersion in the polyester resin is a fine particle having a spherical basic shape and an equivalent spherical equivalent diameter of 2000 nm or less. In the present invention, the size of a resin such as polyethylene or ethylene-butene copolymer existing as a dispersion in the polyester resin is important, including the relationship with the content, in order to ensure the ability to absorb impact energy. .
As an ideal form, since an extremely fine filling state in which the equivalent spherical equivalent diameter of the resin to be dispersed is small is possible, the ability to absorb impact energy can be exhibited with a small content.

  On the contrary, if the diameter of the rubber elastic resin to be dispersed is large, the impact energy absorbing ability is lowered because of a sparse filling state, and the ability to absorb the impact energy cannot be secured unless the content is increased. As a result, the heat resistance described above is reduced, and punch releasability (characterized by the ease with which the punch can be removed from the can body is also called strip-out property) due to high-speed, high-drawing and ironing. Therefore, the phenomenon that the normal can body cannot be obtained easily occurs due to the fact that the upper part of the can body is cramped or is severe and the can body does not come out of the punch.

  Accordingly, the resin such as polyethylene and ethylene-butene copolymer present in the polyester resin is preferably as small as the equivalent sphere equivalent diameter. However, from the viewpoint of stable production and 200 nm from the viewpoint of the content described above. Since the above is a realistic size diameter, the lower limit is set to 200 nm. On the other hand, when the upper limit of 2000 nm is exceeded, it is necessary to increase the content from the viewpoint of securing dent resistance as described above, which is not preferable. Furthermore, the lower limit of the equivalent sphere equivalent diameter is 250 nm or more from the viewpoint of stable production and securing of dent resistance, and both dent resistance and high speed / high working drawing and ironing workability are ensured. From the standpoint of possible, the upper limit is preferably at least 1800 nm or less, and preferably 1500 nm or less as a better equivalent sphere equivalent diameter.

  As described above, since resins such as polyethylene and ethylene-butene copolymer are incompatible with polyester resins, they are dispersed as fine particles having a small equivalent spherical equivalent diameter as in the present invention. However, the boundary between the polyester resin and the resin such as polyethylene or ethylene-butene copolymer is only in contact with each other because there is no chemical bond between them.

Therefore, if processing with a high degree of processing is performed, interface peeling occurs at the boundary between the resins, causing internal defects in the film.
At the site with such internal defects, water, ions, gas, and other substances can be easily transmitted, and the barrier effect is reduced. Therefore, the can filled with the contents is not preferable because metal corrosion is likely to occur, leading to a reduction in the life of the can.
In addition, resins such as polyethylene and ethylene-butene copolymer are resins that do not have a self-adhesion ability with a metal, and thus cause a decrease in adhesion with a metal plate.

In the present invention, for the purpose of avoiding the above-mentioned problem and further ensuring the equivalent spherical equivalent diameter size of a resin such as polyethylene or ethylene-butene copolymer stably within a certain range, The vinyl polymer (V) having
The vinyl polymer (V) having a polar group acts as a compatibilizer between a polyester resin and a resin such as polyethylene or ethylene-butene copolymer, and uses a difference in interfacial tension to make polyethylene or ethylene-butene. A capsule structure is formed in the copolymer resin.
Accordingly, since the resin such as polyethylene or ethylene-butene copolymer is formed as the core portion and the vinyl polymer ((V) is formed as the shell portion, the above-described dispersion structure can be easily taken in the polyester resin. .

Furthermore, since the vinyl polymer (V) serving as the shell portion has a polar group, it is chemically bonded and integrated with the hydroxyl residue or carboxyl residue at the end of the polyester resin, so that the interfacial adhesion between the resins. It is difficult to make internal defects in the film even if processing with a high degree of processing is performed. Furthermore, it has the effect of improving the adhesion to the metal plate.
Examples of the vinyl polymer (V) having a polar group include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, butyl methacrylate, glycidyl methacrylate, and ethylene / methylene acrylate-glycidyl methacrylate copolymer. Acrylic resins can be applied, and one or more of these acrylic resins can also be applied.

  In terms of the content, in the present invention, the polyester film layer (A layer) contains 0.1 parts by mass of rubber elastic resin (R) fine particles having an equivalent spherical equivalent diameter of 2000 nm or less with respect to 100 parts by mass of the mixed polyester resin (A). The vinyl polymer (V) having 1 to 10 parts by mass and the polar group is contained in an amount of 0.01 to 3 parts by mass with respect to 100 parts by mass of the polyester resin (A). As described above, the polyester film layer (A layer) is responsible for the can-making ability mainly corresponding to the drawing and ironing processing at high speed and high processing degree, but also affects the dent resistance. .

Therefore, by including the rubber elastic resin (R) in the polyester film layer (A layer), the dent resistance of the polyester film (F) is improved and the corrosive, for example, contents of cola, sports drink, etc. It can be used with peace of mind.
However, as described above, there is a phenomenon that the release property of the punch is inferior by drawing and ironing by containing the rubber elastic resin (R). As the degree of processing increases, the punch releasability decreases more remarkably.

  However, because of the effects of both the properties of the polyester resin (A) applied to the polyester film layer (A layer) described later and the lubricant contained in the polyester film layer (A layer), a rubber elastic resin is added to the polyester film layer (A layer). Even when (R) is contained, good punch releasability is ensured. However, the improvement of the dent resistance of the polyester film layer (A layer) is a complementary meaning of the improvement of the dent resistance of the entire polyester film (F), and the dent resistance of the polyester film (F) is the polyester film layer (B It is still the same as the layer.

Therefore, in the present invention, the content of the rubber elastic resin (R) in the polyester film layer (A layer) is in the range of 0.1 to 10 parts by mass.
When the upper limit of 10 parts by mass is exceeded, there is a relationship with the content of the rubber elastic resin (R) contained in the polyester film layer (B layer) described above, but the dent resistance is good. However, since the film itself is softened, it adheres to the punch or becomes easy to bite, and the release property of the punch is lowered. For example, the thickness reduction rate is 25 at a processing speed of about 40 cans / minute. %, Locally even under drawing and ironing conditions of about 50%, punch release is inferior and buckling occurs in the opening of the can body, and a can body with a normal can height may not be obtained. It is not preferable.

  On the other hand, when the amount is less than 0.1 parts by mass, there is a slight influence on the equivalent spherical equivalent diameter of the rubber elastic resin (R) that is dispersed, but the impact energy of the polyester film layer (A layer) is almost not absorbed. When the polyester film layer (A layer) is not seen and microcracks occur and is filled with highly corrosive contents, the effect of improving the dent resistance is not observed.

  The amount of the rubber elastic resin (R) to be contained in the polyester film layer (A layer) is 0.1 to 10 parts by mass. In particular, the plate thickness reduction rate is 50% or more at a processing speed of 60 cans / minute or more. In the case of performing high-speed and high-working drawing and ironing and filling highly corrosive contents, the range of 1 to 7 parts by mass is particularly preferable. Content of the vinyl polymer (V) which has a polar group is 0.01-3 mass parts with respect to 100 mass parts of polyester resins (A).

  Since the vinyl polymer (V) having a polar group acts to ensure the dispersibility and modify the resin such as polyethylene and ethylene-butene copolymer, the content of the vinyl polymer (V) having a polar group Needless to say, it is necessary to select appropriately according to the content of polyethylene or ethylene-butene copolymer resin, but in terms of mass part ratio of vinyl polymer (V) and polyethylene or ethylene-butene copolymer resin. About 0.1 to 0.3 is a preferable range.

  Therefore, even if it exceeds 3 parts by mass, the effect becomes saturated with respect to the formation of the shell part, which is not economical. The polyester film layer (B layer) is a vinyl polymer having 5 to 40 parts by mass of rubber elastic resin (R) fine particles having an equivalent spherical equivalent diameter of 2000 nm or less and a polar group with respect to 100 parts by mass of the mixed polyester resin (B). 1 to 10 parts by mass of (V) is contained with respect to 100 parts by mass of the polyester resin (B).

As described above, the polyester film layer (B layer) is mainly responsible for improving the dent resistance. When the content is less than 5 parts by mass, when the rubber elastic resin (R) contained in the polyester film layer (A layer) is small, the ability to absorb impact energy is not sufficient, and the polyester film (F) is resistant. Since the dent property may not be secured, it is not preferable.
On the other hand, when the content exceeds 40 parts by mass, the dent resistance as the polyester film (F) can be sufficiently secured. For example, when the rubber elastic resin (R) is not contained in the polyester film layer (A layer). However, since the characteristics of polyethylene and ethylene-butene copolymer contained in the polyester film layer (B layer) are developed, the heat resistance is reduced, and the punch is separated by high-speed, high-processing drawing and ironing. This is not preferable because the phenomenon that the mold is inferior and a normal can cannot be obtained appears.

  Content of the vinyl polymer (V) which has a polar group is the range of 1-10 mass parts with respect to 100 mass parts of polyester resins (B). Since the polyester film layer (B layer) is a film in contact with the metal plate, it is necessary to ensure adhesion with the metal plate. If the amount is less than 1 part by mass, an amount sufficient to form a shell part in a resin such as polyethylene or ethylene-butene copolymer is formed. This is not preferable because the danger and the risk of insufficient adhesion to the metal plate increase.

  On the other hand, if it exceeds 10 parts by mass, the shell part becomes excessive with respect to the formation and the effect is saturated, which is not economical. Further, as described above, the vinyl polymer (V) having a polar group has both ensuring dispersibility and ensuring reactivity of a rubber elastic resin such as polyethylene and ethylene-butene copolymer in a polyester resin. Needless to say, the content of the vinyl polymer (V) having a polar group should be appropriately selected according to the content of polyethylene or ethylene-butene copolymer resin. About 0.1 to 0.3 is a preferable range in terms of a mass part ratio of polyethylene and ethylene-butene copolymer resin.

Next, the polyester resin (A) and the polyester resin (B) applied to the present invention will be described.
The polyester resin (A) applied as the polyester film layer (A layer) has a melting point (A-Tm) of 235 ° C. or higher, an intrinsic viscosity (A-IV) of 0.60 or higher, and a heat of crystal melting (A-Hm). And / or a polyester resin having a cold crystallization heat (A-Hc) of 25 to 50 J / g and a glass transition temperature (A-Tg) of 65 ° C. or higher contains a lubricant, a heat stabilizer and / or an antioxidant. It consists of a polyester resin (A).

  As described above, the polyester film layer (A layer) is mainly responsible for high speed and high workability canability. Accordingly, since the polyester film layer (A layer) is a film that is in direct contact with the punch, heat resistance is the most important requirement, and the melting point (A-Tm) is 235 ° C. or higher. If the melting point (A-Tm) is 235 ° C. or higher, the punch releasability is high-speed and high-working ironing even when 10 parts by mass of the rubber elastic resin of the polyester film layer (A layer) is contained. Phenomena such as inferior cramping at the upper part of the can body and phenomena such as the punch not being removed from the formed can body are avoided, and good canability is ensured.

  The upper limit of the melting point (A-Tm) of the polyester resin (A) is not particularly limited, but from the viewpoint of punch releasability, no further effect is observed even when the temperature exceeds 260 ° C. Since the resin generally has a high melting point and tends to be a strong crystalline resin, the temperature is preferably 260 ° C. or lower. In the present invention, the intrinsic viscosity (A-IV) of the polyester resin applied to the polyester film layer (A layer) is 0.60 or more. Since the polyester film layer (A layer) is a film that is in direct contact with the punch as described above, it is necessary to withstand the surface pressure applied during the ironing process.

  In addition, polyester resins with high intrinsic viscosity (IV) have characteristics such as high mechanical strength and resistance to crystallization due to heat. It is in the direction where the fall of an elongation characteristic is eased. Therefore, in the present invention, the intrinsic viscosity (A-IV) of the polyester resin applied to the polyester film layer (A layer) is 0.60 or more for the above reason. When the intrinsic viscosity (A-IV) of the polyester resin is less than 0.60 dl / g, the dent resistance is slightly inferior depending on the magnitude of impact and impact, and fine cracks are formed in the polyester film layer (A layer). Is not preferable.

  As described above, the higher the intrinsic viscosity (IV), the higher the mechanical strength of the film, and the impact fracture strength tends to be the same. For highly corrosive contents such as cola and sports drinks, In addition, it is preferable to apply a higher polyester resin for the intrinsic viscosity (IV). From this sense, it is safer that the intrinsic viscosity (A-IV) of the polyester resin used for the polyester resin film layer (A) is higher. is there. However, forming a film from a polyester resin having a high intrinsic viscosity (IV) increases the production cost because the melt viscosity is high, and the power of the extruder for extruding in layers with a T die is required. In addition, because the frictional heat generated in the extruder raises the melting temperature, the resin is more likely to be thermally decomposed, which leads to a decrease in molecular weight. It may be said that a polyester resin film having an extremely high intrinsic viscosity (IV) cannot be obtained.

  In the present invention, the upper limit of the intrinsic viscosity (A-IV) is not particularly limited, but is preferably 2.00 dl / g or less in view of the above-described productivity. Therefore, the preferable range of intrinsic viscosity is 0.65 to 2.00 dl / g, more preferably 0.70 to 2.00 dl / g. In the present invention, the heat of crystal melting (A-Hm) and the heat of cold crystallization (A-Hc) of the polyester resin applied to the polyester film layer (A layer) are 25 to 50 J as one or both characteristic values. / G.

  The heat of crystal fusion (Hm) and the heat of cold crystallization (Hc) both indicate the crystallinity of the resin in terms of calorie, and the heat of cold crystallization (Hc) is the amount of resin per unit mass crystallized by heat. The heat of crystal fusion (Hm) is expressed in terms of the amount of heat, and is the amount of heat that is melted by the resin crystallized by heat per unit mass. Accordingly, a large heat of cold crystallization (Hc) indicates a large amount of crystallization, and a large heat of crystal fusion (Hm) indicates a large amount of crystallization.

  As described above, in the ironing process at high speed and high processing degree, the polyester resin is crystallized and stretched, and in some cases, the film is cracked circumferentially in the can height direction. Therefore, it is not preferable to apply a resin having a large heat of crystal melting (Hm) and a heat of cold crystallization (Hc). However, in the present invention, the occurrence of circumferential cracks as described above is avoided by the presence of the polyester film layer (B layer). Therefore, the polyester film layer (A layer) is mainly used for punch releasability. The characteristic with respect to is maintained. Nonetheless, when a crack occurs severely in the polyester film layer (A layer), the crack propagates to the polyester resin film layer (B) and causes a crack to occur in the polyester film layer (B layer). Is naturally not preferred.

  Therefore, in the present invention, the heat of crystal melting (A-Hm) and the heat of cold crystallization (A-Hc) of the polyester resin applied to the polyester film layer (A) are 25 to 50 J / as one or both characteristic values. The range is g. If it is less than 25 J / g, the releasability of the punch is inferior, so the phenomenon that the upper part of the can body is cramped as described above, or the phenomenon that the punch does not come off at all when it is severe may occur. It is not preferable.

  In particular, when the ironing process is performed at a high speed of 60 cans / minute or more, or when the processing degree is a high processing degree of 50% or more, there is a high risk that such a phenomenon will appear remarkably. Therefore, it goes without saying that even if it is less than 25 J / g, there is a case where molding can be performed without any problem when the ironing process is performed at a low speed and the processing degree is low. On the other hand, if it exceeds 50 J / g, the release property of the punch is good, but fine cracks are likely to occur in the film, which may affect the soundness of the polyester film layer (B layer) film. It is not preferable.

  The glass transition temperature (A-Tg) is 65 ° C. or higher. The glass transition temperature (Tg) is also a requirement related to the releasability of the punch. When the glass transition temperature (A-Tg) is less than 65 ° C., the film softens due to heat generated during the ironing process and sticks to the punch, or the punch bites into the film due to local high surface pressure. As a result, the releasability of the punch is inferior, the phenomenon that it is cramped at the upper part of the can body mentioned above and the phenomenon that the punch does not come off from the molded can body may occur, It is not preferable.

The upper limit of the glass transition temperature (A-Tg) is not particularly limited, but generally, the above-described ability to absorb impact energy at low temperatures is higher when the glass transition temperature is lower. Even if the polyester film layer (A layer) and the polyester film layer (B layer) contain a rubber elastic resin, 110 ° C. or less is preferable from the viewpoint of dent resistance. In the present invention, the polyester film layer (A layer) contains 0.5 to 1.0% by mass of a lubricant having an average particle size of 0.4 to 2 μm. The lubricant plays an important role as an auxiliary agent for improving the releasability of the punch, but it is not preferable if it is too small.
That is, in drawing and ironing, particularly in ironing, a very high surface pressure is applied at the point of action between the punch surface and the die. Such a surface pressure bears a role directly supported by the polyester film layer (A layer) on the inner surface side film side.

If the size of the lubricant is less than 0.4 μm, this surface pressure cannot be supported, and it will be applied directly to the polyester film layer (A layer), increasing the rate of biting into the punch, and reducing the releasability of the punch. It is not preferable because it causes.
On the other hand, if the size of the lubricant exceeds 2 μm, it exhibits a sufficient effect for supporting this surface pressure, but the phenomenon that the film surface is damaged by the lubricant when the punch comes off may occur. The soundness of the inner film is impaired, which is not preferable.

  The same applies to the content. If the content is less than 0.5% by mass, the amount sufficient to support the surface pressure is insufficient, which causes a decrease in punch releasability. On the other hand, if the amount exceeds 1.0% by mass, the amount is so large that the chance of damaging the inner film when the punch is removed is increased, and on the contrary, soundness cannot be secured, which is not preferable. The lubricant contained in the polyester film layer (A layer) is optimally containing fine particles having a particle size of 0.5 to 1.5 μm in a range of 0.5 to 1.0 mass%.

As a lubricant, for example, silicon oxide, aluminum oxide and the like are representative examples, but silicon oxide is optimal from the viewpoint of hardness as a lubricant and uniformity of particle size, but these can also be used in combination.
The polyester resin (B) applied as the polyester film layer (B layer) has a melting point (B-Tm) of 235 ° C. or higher, an intrinsic viscosity (B-IV) of 0.60 or higher, and a heat of crystal melting (B-Hm). And / or polyester resin having a cold crystallization heat (B-Hc) of 25 to 50 J / g and a glass transition temperature (B-Tg) of 45 ° C. or higher, containing a lubricant, a heat stabilizer and / or an antioxidant. It is a waste. The melting point (B-Tm) of the polyester resin applied to the polyester film layer (B layer) is 220 ° C. or higher.

  As described above, in the polyester film-coated metal plate of the present invention, it is mainly the polyester film layer (A layer) that is responsible for ensuring high-speed and high workability, but the polyester film layer (B layer). Is not at all involved, when the melting point (B-Tm) of the polyester resin used for the polyester film layer (B layer) is less than 220 ° C, for high-speed, high-working molding, or only for drawing There is no problem with moldability, but especially when ironing is performed, the punch releasability is inferior and it is difficult to remove the punch from the molded can body. There is a case where the phenomenon that the punch does not come off at all occurs.

  This phenomenon is mainly due to the processing heat and the heat storage of that heat in the mold, so the method of cooling the mold is a way to suppress the heat storage in the mold and reduce the effect on the film. Although it has been proposed, the higher the speed, the more difficult the cooling rate can catch up, and there is a natural limit. From this point of view, the melting point (B-Tm) of the polyester film layer (B layer) is important. The melting point (B-Tm) of the film layer (B layer) is 220 ° C. or higher. If the melting point (B-Tm) of the polyester film layer (B layer) is 220 ° C. or higher, there is no problem as long as it is within the range of processing speed and processing degree described later, and the releasability of the punch does not become a problem. Continuous molding is possible.

In the present invention, the upper limit of the melting point (B-Tm) of the polyester film layer (B layer) is not particularly limited, but the melting point is higher than the melting point (A-Tm) of the upper polyester film layer (A layer). In the case of a polyester resin having a thickness of not higher than 260 ° C., it is not preferable from the viewpoint of laminating properties when coated on a metal plate. Further, the melting point (A-Tm) of the polyester film layer (A layer) is within −30 ° C., preferably the melting point (A−Tm) of the polyester film layer (A layer) is within −25 ° C. Furthermore, it is preferable because the film shrinkage of the polyester film layer (A) is suppressed by heat treatment when the density of the film described below is 1.360 g / cm ³ or less.

  The heat of crystal melting (B-Hm) and / or the heat of cold crystallization (B-Hc) of the polyester film layer (B layer) is in the range of 20 to 45 J / g. Usually, in the case of drawing and ironing, in order to obtain a desired can size, for example, a beer can size of 350 ml, two or three times of ironing, that is, multi-stage ironing, is performed to prevent breakage of the metal plate of the can body. It is common to go.

  As described above, in ironing processing at high speed and high processing degree, the polyester resin is crystallized and stretched in the can height direction at the same time due to heat generated during processing. As a result, the elongation characteristics of the polyester resin film will be lower than before molding, and depending on the polyester resin, it will not be possible to follow the molding, and the film will be cracked circumferentially in the can height direction. If this phenomenon occurs, it may lead to breakage of the metal plate.

  When the metal plate breaks, it is necessary to remove the debris, and the line is stopped, resulting in a significant reduction in productivity. Further, even if the film breaks, the can body cannot secure the soundness of the coated film, so that it cannot be a practical can, resulting in an unfavorable result. Since such a phenomenon is caused by the crystallinity of the polyester resin, it is not preferable to apply the resin having a large heat of crystal melting (Hm) and heat of cold crystallization (Hc) described above.

However, a resin having a small crystal melting heat (Hm) and a cold crystallization heat (Hc), which is a crystalline polyester resin, is generally soft, so that the polyester film layer (A layer) is present. The problem that it is inferior in the releasability of the punch which occurred is generated.
Therefore, in the present invention, the heat of crystal melting (B-Hm) and the heat of cold crystallization (B-Hc) of the polyester resin applied to the polyester film layer (B layer) are 20 to 45 J as one or both characteristic values. / G.

  If it is less than 20 J / g, the punch releasability is inferior, so that the phenomenon that the upper part of the can is cramped as described above, or the phenomenon that the punch does not come off at all when it is severe may occur. Absent. In particular, when the ironing process is performed at a high speed of 60 cans / minute or more, or when the processing degree is a high processing degree of 50% or more, there is a high risk that such a phenomenon will appear remarkably. Therefore, it is needless to say that even if it is less than 20 J / g, molding can be performed without any problem when the ironing process is performed at a low speed and the processing degree is low.

  On the other hand, if it exceeds 45 J / g, the mold releasability is good, but fine cracks are likely to occur in the film, and it may be difficult to ensure the soundness of the film, which is not preferable. In this invention, the glass transition temperature (B-Tg) of the polyester resin applied to a polyester film layer (B layer) is 45 degreeC or more. As described above, since the polyester resin film layer (B layer) is a film layer mainly responsible for improving dent resistance, it goes without saying that a soft resin is basically better.

  However, even though the polyester film layer (A layer) exists, if the polyester film layer (B layer) is too soft, punch releasability is particularly poor during ironing, and high speed and high workability In many cases, a normal can body cannot be obtained or the can does not come out of the punch. Of course, this phenomenon is influenced by the glass transition temperature (A-Tg) of the resin of the polyester film layer (A layer) described above and the crystallinity of the polyester film layer (A layer) and the polyester film layer (B layer). However, there is also an influence of the glass transition temperature (B-Tg) of the polyester film layer (B layer). If the glass transition temperature (B-Tg) of the polyester film layer (B layer) is less than 45 ° C., it is too soft. The object of the present invention cannot be achieved.

  The glass transition temperature (B-Tg) of the polyester film layer (B layer) is preferably 48 [deg.] C. or higher, which ensures good punch release properties. Although the upper limit of the glass transition temperature (B-Tg) of the polyester film layer (B layer) is not particularly limited, as described above, the ability to absorb impact energy at low temperatures is generally glass. Since the lower transition temperature is higher, the temperature is preferably 110 ° C. or lower from the viewpoint of dent resistance as in the case of the polyester film layer (A layer).

  In the present invention, the intrinsic viscosity (B-IV) of the polyester resin applied to the polyester film layer (B layer) is 0.55 dl / g or more. The intrinsic viscosity (IV) is an index indicating the average molecular weight of the polyester resin, and the higher the intrinsic viscosity (IV), the larger the average molecular weight. The mechanical properties of the polyester resin film are directly related to the dent resistance in the case of the same resin composition. For example, as described above, the mechanical properties such as the impact fracture strength of the film have an intrinsic viscosity (IV). In order to improve the dent resistance, which is the object of the present invention, a film made of a polyester resin having a high intrinsic viscosity (IV) has been proposed in many cases.

In the present invention, by including the rubber elastic resin (R) described above, the intrinsic viscosity (B-IV) of the polyester resin used for the polyester film layer (B) can be applied up to 0.55 dl / g, Even at this intrinsic viscosity (IV), good dent resistance is ensured.
However, as described above, since the impact fracture strength of the film is higher as the intrinsic viscosity (IV) is higher, the intrinsic viscosity (IV) is higher for highly corrosive contents such as cola and sports drinks. It is preferable to apply a polyester resin. From this point of view, the intrinsic viscosity (B-IV) of the polyester resin used for the polyester film layer (B layer) is preferably 0.60 dl / g or more, more preferably 0.00. 65 dl / g or more is good.

  Although the upper limit of the intrinsic viscosity (B-IV) is not particularly limited, as described above, forming a film from a polyester resin having a high intrinsic viscosity (IV) increases the production cost. Therefore, it is preferably 2.00 dl / g or less from the viewpoint of productivity. Therefore, the range of preferable intrinsic viscosity is 0.60 to 2.00 dl / g, and more preferably 0.65 to 2.00 dl / g. In the present invention, the lubricant contained in the polyester film layer (B layer) is not particularly limited, but for example, a lubricant such as silicon oxide, aluminum oxide, etc., 0.1 to 0.5 μm fine particles, 0 to 0.5 mass. % Can be contained.

  The polyester resin of the polyester film layer (A layer) and the polyester film layer (B layer) applied in the present invention is based on a crystalline polyester resin as a basic resin. As an example, terephthalic acid is used as an acid component. Aromatic dicarboxylic acids such as isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, fumaric acid, succinic acid, maleic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, A copolymer or blend of a polyester resin composed of an aliphatic glycol such as ethylene glycol, butanediol, propanediol, or pentanediol as a glycol component, or an alicyclic glycol such as cyclohexanedimethanol, has the above melting point (Tm), crystal Limited range of heat of fusion and heat of cold crystallization If so, it can be applied.

  Furthermore, the polyester resin of the polyester film layer (A layer) and the polyester film layer (B layer) contains a heat stabilizer and / or an antioxidant. Polyester resin is a resin that causes thermal decomposition and hydrothermal decomposition, in which bonds in a molecule are broken by heat during film formation, heat during lamination, and heat during retort sterilization. In particular, decomposition with hot water occurs at a faster rate than thermal decomposition. Of course, when thermal decomposition or hydrothermal decomposition occurs, the molecular weight decreases, and as a result, the mechanical properties of the film itself deteriorate. In addition, the crystallization speed is increased and crystallization is facilitated.

  This causes a decrease in the formability of the laminated metal plate and a decrease in the dent resistance of the resulting can body. In order to avoid such a phenomenon, in the present invention, a polyester resin containing a heat stabilizer and / or an antioxidant is used. Although it does not specifically limit as a heat stabilizer, A phosphite ester type stabilizer is suitable, and bis (2,4-di-tert-butyl) phenyl phosphite, bis (2, 4-dicumylphenyl) pentaerythritol-di-phosphite, and the like.

  The antioxidant is not particularly limited, but examples thereof include: tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane, tetrakis [methylene-3- (3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, and the like. As content, 1 type (s) or 2 or more types of a thermal stabilizer and antioxidant are contained in the range of 0.01-3 mass parts with respect to 100 mass parts of polyester resins.

  If the amount is less than 0.01 part by mass with respect to 100 parts by mass of the polyester resin, the effect of suppressing the above-described thermal decomposition and hydrothermal decomposition is not sufficient, and the punch releasability is deteriorated and microcracks of the film are generated in the molding process. In some cases, the phenomenon that the dent resistance of the resulting can deteriorates may appear, which is not preferable. On the other hand, when it exceeds 3 parts by mass with respect to 100 parts by mass of the polyester resin, the above-described molding process causes a decrease in punch releasability and microcracks in the film, and a decrease in dent resistance of the resulting can. Of course, this phenomenon is avoided and good moldability and dent resistance are ensured, but the effect is not only saturated, but the phenomenon that the transparency of the film is locally whitish may appear. The film appearance may be impaired, which is not preferable.

  In the present invention, the polyester resin can be blended with an ultraviolet absorber, a plasticizer, a pigment, an antistatic agent, a lubricant, a crystal nucleating agent, and the like as necessary. The method for producing the polyester resin (A) and the polyester resin (B) in the present invention is not particularly limited. That is, it can be used even if it is produced by either the transesterification method or the direct polymerization method. Moreover, in order to raise intrinsic viscosity (IV), what was manufactured by the solid phase polymerization method may be used. Furthermore, from the point of reducing the amount of oligomers eluted from the polyester resin in the retort sterilization treatment, pastro sterilization treatment, etc. carried out after filling and sealing the contents in the can, the oligomer content produced by the reduced pressure solid phase polymerization method is It is preferred to use a low polyester.

  Speaking of the film thickness covered with the metal plate, in the present invention, the polyester resin film layer (A layer) has a thickness of 5 to 20 μm, the polyester resin film layer (B layer) has a thickness of 5 to 25 μm, and a polyester film ( The total thickness of F) is 10 to 40 μm. Further, from the thickness constitution ratio of the polyester film layer (A layer) and the polyester film layer (B layer), the thickness ratio of the A layer / B layer is preferably in the range of 0.4 to 1.0.

  When the film thickness of the polyester film (F) laminated on the laminated metal plate before forming is less than 10 μm, depending on the degree of processing, the portion where the film thickness of the can body after forming is about 3 to 4 μm is localized. Therefore, it is difficult to ensure film soundness, and even if soundness can be ensured, the barrier effect to suppress the permeation of the content is reduced, so the long-term content preservation is poor, It may be insufficient in terms of corrosion resistance, which is not preferable.

Also, in terms of dent resistance, if the thickness of the polyester film layer (B layer) is less than 5 μm or the total film thickness is less than 10 μm, the impact energy cannot be absorbed sufficiently, and the film has cracks. It may occur, which is not preferable from this point.
On the other hand, when the thickness of the film laminated on the laminated metal plate exceeds 40 μm as a total thickness, it exhibits sufficient performance in terms of corrosion resistance and dent resistance, but the effect is saturated and not economical. In addition, since the total thickness of the laminated metal plate is increased, the surface pressure during processing is increased, and depending on the degree of processing, it may cause a decrease in punch releasability, which is not preferable.

Of course, as for the thickness of the polyester resin film (F), a thin film can be applied when the degree of processing is small, and a thick film can be applied when the degree of processing is large from the viewpoint of storage stability of the contents. Needless to say, the application of a thick film is preferably within a range in which the releasability of the punch can be ensured because of the balance with moldability.
Further, regarding the film thickness, as described above, the ratio of the thickness of the polyester film layer (B layer) to the thickness of the polyester film layer (A layer) is as follows: polyester film layer (A layer) thickness / polyester film layer (B layer) The optimum thickness is 0.4 to 1.0.
When the ratio of the thickness of the polyester film layer (A layer) / the thickness of the polyester film layer (B layer) is less than 0.4, when the total thickness is increased, the characteristics of the polyester film layer (B layer) are greatly expressed and the dent resistance is increased. However, it is not preferable because the heat resistance and mechanical properties of the entire film are lowered, leading to poor punch releasability.

  On the other hand, when the ratio of the thickness of the polyester film layer (A layer) / the thickness of the polyester film layer (B layer) exceeds 1.0, particularly when the total thickness is reduced, the characteristics of the polyester film layer (B layer) are sufficient. Even if it is exerted, the impact fracture strength is reduced due to the influence of the thickness factor, and as a result, the dent resistance is lowered, cracks are generated in the film, and the corrosion resistance may be lowered. The ratio of the thickness of the polyester film layer (A layer) / the thickness of the polyester film layer (B layer) is such that the thickness of the polyester film layer (B layer) is 5 μm or more, and the total thickness with the polyester film layer (A layer) is 10 If it is in the range of ˜40 μm, the range of 0.4 to 1.0 is optimal from the standpoint of can manufacturing and dent resistance.

Next, the metal plate used in the present invention will be described.
In the present invention, a steel plate, an aluminum plate, or an aluminum alloy plate is applied as the metal plate. The steel sheet is not particularly limited in terms of mechanical properties such as plate thickness and tensile breaking strength, and is normally used as a steel plate for cans, specifically for drawn cans, drawn and ironed cans, and lids. The steel plates used for each of the above are applied. The same applies to the surface treatment applied to the surface of the steel plate, commonly referred to as TFS-CT, with 80 to 150 mg / m ² of metal chromium as the amount of adhesion on one side of the steel plate, and 10 to 10 in terms of metal chromium on the upper layer. electrolytic chromic acid treated steel sheet having a hydrated chromium oxide film of ^{20mg / m 2, 50~1000mg / m} 2 as an adhesion amount of one side on both sides of the steel sheet, hydration of 10 to 15 mg / m ² reckoned as metal chromium thereon Ni-plated steel sheet having a chromium oxide film, Ni plating layer of ^{20 to} 2000 mg / m ² as a single-side adhesion amount on both surfaces of the steel plate, and an organic resin of 1 to 100 mg / m ² as the adhesion C amount of one side as an upper layer. It is widely applied to Ni-chemically treated steel plates having a chemical conversion film layer.

The same applies to aluminum plates and aluminum alloy plates, and the mechanical properties such as plate thickness and tensile breaking strength are not particularly limited, and are usually used as aluminum plates for cans, specifically drawn and ironed cans. The aluminum plate used for each use for the lid and the lid is applied. As for the surface treatment of the aluminum plate or the aluminum alloy plate, a chromium phosphate-treated aluminum plate subjected to a chemical conversion treatment of 10 to 60 mg / m ² as a chromium adhesion amount on one side was applied to both surfaces of the aluminum plate and other chemical conversion treatments. Widely applied to aluminum plates and aluminum alloy plates.

  The film for obtaining the polyester film-coated metal plate of the present invention may be any of a biaxially stretched film, a uniaxially stretched film, and a non-oriented film regardless of the history of film formation. As an example of the method for coating the metal plate of the present invention with the polyester film (F), at least one surface of the metal plate heated to a temperature equal to or higher than the melting point of the polyester film layer (B layer) After coating the metal plate with a known method such as a method of laminating a film using a laminating roll so that the B layer is in contact with the metal plate, the polyester film layer (A A layer obtained by heating the metal plate as a plate temperature to a temperature equal to or higher than the melting point of the layer) or higher than the melting point of the optional film coated on the other side of the metal plate, and then immediately cooling with water or / and compressed air. Is applicable.

The other surface of the metal plate can be any film or painted.
When an arbitrary film is applied, as a matter of course, it is necessary to set the plate temperature on the basis of the higher melting point of the metal plate, and both the double-sided simultaneous lamination and the sequential lamination are possible. Heating methods such as heating in an electric furnace, heating with hot air, heating in contact with a heating roll, induction heating at high frequency, etc. are used as the heating method for the metal plate during primary bonding. However, when heating the metal plate as a plate temperature to a temperature equal to or higher than the melting point of the polyester film layer (A layer) performed subsequently, or higher than the melting point of the optional film coated on the other side of the metal plate, Since the polyester film is coated, non-contact heating such as a method of heating in an electric furnace, a method of heating with hot air, a method of induction heating at high frequency, etc. is preferable, and it is better not to employ a contact heating method such as a heating roll. Needless to say.

In addition, as a method of rapid cooling, it is possible to adopt a method of cooling by blowing compressed air or cooled compressed air, or a method of cooling by immersing in water or the like alone or in combination.
In the present invention, the density of the polyester film (F) coated on the metal plate is not particularly limited, but the density of the entire two-layer film of the polyester film layer (A layer) and the polyester film layer (B layer) is 1.360 g / cm ³ or less is desirable.
A density of 1.360 g / cm ³ or less indicates that the coated film is in an amorphous state or a state that is very close to an amorphous state.

The reason why the density of the polyester film (F) coated on the metal plate before forming is preferably 1.360 g / cm ³ or less is to make the film follow the drawing and ironing process. If the density of the polyester film exceeds 1.360 g / cm ³ , the elongation characteristics of the film will decrease, and in particular, the thickness reduction rate of the can wall part is large. This is because the soundness of the inner surface film of the can may not be ensured. If the soundness of the inner surface film of the can cannot be ensured, it develops into corrosion of the base metal, which is a problem in terms of the preservation of the contents, which is not preferable.

Therefore, when the density of the polyester film (F) corresponding to the inner surface side of the can is 1.360 g / cm ³ or less, the soundness of the inner surface film of the can can be secured, and the drawn and ironed can with excellent corrosion resistance Is desirable because it can be achieved. In order to make the whole density of the polyester film (F) of the present invention 1.360 g / cm ³ or less, after the primary adhesion, the plate is continuously kept at a temperature equal to or higher than the melting point of the polyester resin film layer (A layer). When the metal plate is heated as a temperature, especially when the supplied film is a biaxially stretched film or a uniaxially stretched film, it must be sufficiently melted to break the crystals, and further, it will not cause crystallization during the cooling process. It is essential.

The above-mentioned rapid cooling conditions are important, and it is important that the heat transfer coefficient on the polyester resin film surface is 0.0005 cal / cm ² · sec · ° C. or more and less than 0.005 cal / cm ² · sec · ° C. It is. As a method of rapid cooling, it is possible to employ a method of cooling by blowing compressed air or cooled compressed air, or a method of cooling by immersing in water or the like alone or in combination.

Next, a polyester film-coated metal can which is the second of the present invention will be described.
As for the metal can of the present invention, the can body is basically a seamless can obtained by drawing or drawing / ironing as described above. Examples of cans according to the present invention include: (1) After drawing and ironing, the opening is trimmed to a normal can height, and then the opening is further drawn so that the mouth becomes the diameter of the can body. A seamless can that is formed by processing (flange processing) the flange so that the can lid can be tightened after processing to a smaller diameter (neck-in processing). As a specific example, in the case of a 350 ml beer can size, the outer diameter of the can body is 211 (2 inches + 1/16 inch) and the lid of 204 (2 inches + 4/16 inch) is tightened. As can be seen, a seamless can with a drawn opening in the can body is raised.

(2) Seamless cans are made by drawing and ironing, and then the seamless can openings are further drawn to form shoulders and cap diameters so that they can be closed with caps. Seamless cans such as re-bottled bottles that have been cut.
(3) Making a seamless can by drawing and ironing, then drawing the bottom of the can, trimming the neck to the diameter that can be molded into the shoulder and cap, and then closing the can with a cap Seamless cans such as re-capable bottle-type cans, threaded as possible, while a can lid is wrapped around the original opening of the seamless can. Etc. are raised.

Therefore, the degree of processing of the can wall portion expressed by Equation 1 described above varies depending on the shape of the can finally obtained in the seamless can of the present invention, but the degree of processing is optimally 25% or more and 70% or less. Range. And the density of the polyester film (F) coat | covered by the at least inner surface side of the metal can in this invention is 1.360 g / cm < ³ > or less. That the density is 1.360 g / cm ³ or less means that it is substantially in an amorphous state or very close to an amorphous state as described above.

The first reason why the density of the polyester film coated on the metal can in the present invention is 1.360 g / cm ³ or less is to ensure the formability of the next step.
That is, a can made by drawing and ironing a polyester film-coated metal plate is further drawn on the opening as described above, and the mouth is made smaller than the diameter of the can body. It is called an easy-open end, commonly known as an aluminum easy-to-open lid, which is called “flange processing”. This is generally due to cost reduction of EOE).

The neck-in process and the flange process are more severe as the diameter of the mouth is larger, and film peeling tends to occur at this part. Of course, the can where the film has peeled may be problematic because the peeled portion is exposed to the contents, leading to corrosion of the base metal.
In order to avoid such a problem, it is necessary that the stretch characteristics of the coated film and the adhesion between the base metal and the base metal are good. For that purpose, the coated polyester film is preferably in an amorphous state, This is achieved by setting the density to 1.360 g / cm ³ or less.

Further, in the case of the above-described recapable bottle type can, since the molding process is subjected to more severe processing than the processing of a normal seamless can, the density of the polyester film is 1.360 g / cm ³ or less. There is a need to. The second reason why the density of the polyester resin film coated on the metal can in the present invention is 1.360 g / cm ³ or less is to ensure dent resistance.

  The rubber elastic resin (R) called the polyethylene or ethylene-butene copolymer of the present invention is dispersed in the polyester film layer (B layer) in a spherical state before the molding process. Stretched violently in the direction. In such a state, the rubber elastic resin (R) also has a large amount of molding strain accumulated in the resin, so that the ability to absorb impact energy is reduced, and as a result, the effect of improving dent resistance is reduced. In order to recover such a situation, it is sufficient to release the strain by applying heat, but at a temperature below the melting point of the polyester resin, the polyester resin itself crystallizes, and the impact fracture strength of the polyester resin itself is reduced. Decreasing the dent resistance may sometimes result in a decrease.

Therefore, the density of the polyester resin film is set to 1.360 g / cm ³ or less. In this state, as described above, the polyester resin is substantially in an amorphous state or very close to an amorphous state. In such a state, the rubber elastic resin (R) becomes spherical again and the characteristics are sufficiently high. It can be used to ensure excellent dent resistance. As a method of making the polyester resin film coated on the metal can obtained by drawing and ironing substantially amorphous and making the density 1.360 g / cm ³ or less, the can body is made of a polyester film layer (A It is obtained by rapidly cooling after heating to the melting point or higher of the layer) and remelting.

  The process of making the polyester film (F) coated by heating the can body amorphous is as follows: (1) Molding with a degreasing agent before trimming the can mouth of the metal can obtained by drawing and ironing After degreasing the processing lubricant, at least the trimmed opening is made amorphous. (2) The metal can obtained by drawing and ironing is heated to volatilize the molding processing lubricant and at the same time amorphous (3) After trimming, if it is a seamless can, before processing the neck and flange, if it is a re-capable bottle-type can, at least the relevant part will be made amorphous before threading, etc. This process can be performed. Which process and what means can be used can be selected as appropriate in relation to the equipment.

  As a method for heating the can, a heating method such as a method of heating in an electric furnace, a method of heating with hot air, a method of induction heating at high frequency, or the like can be adopted. Therefore, it is also possible to heat a metal can using the heat of the coating / printing process applied to the outer surface of the metal can. Further, as a method of rapid cooling, a method of cooling by blowing compressed air or cooled compressed air can be employed. Depending on the situation, a method of cooling by immersing in water or the like is also possible.

Hereinafter, the effects of the method of the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto. The evaluation methods performed in this example are as follows.
(1) The melting point (Tm) of the polyester resin film is 10 mg of polyester film, and in a nitrogen stream, a differential scanning calorimeter (DSC) shows an exothermic / endothermic curve (DSC curve) at a temperature rising rate of 10 ° C./min. When measured, the integrated intensity of the exothermic part is the cold crystallization heat Hc (J / g), the integrated intensity of the endothermic part is the crystal melting heat Hm (J / g), and the peak temperature of the endothermic peak accompanying melting is the melting point Tm ( ° C).

(2) The density of the polyester resin film was measured by a density gradient tube method.
(3) The intrinsic viscosity (IV) of the polyester was measured at 25.0 ± 0.1 ° C. by dissolving 0.100 ± 0.003 g of the polyester film in the orthochlorophenol solution using an Ubbelohde viscometer.
(4) Equivalent sphere equivalent diameter of rubber elastic resin, dispersion state, and dispersion state of vinyl polymer are the state of presence in the polyester resin film by dyeing with a ruthenium acid after cutting out an ultrathin section of the laminate material with a microtome. It examined by observing with the transmission microscope.

  (5) The glass transition temperature of the polyester film layer (A layer) and the polyester film layer (B layer) is polyester when creating a two-layer film consisting of a polyester film layer (A layer) and a polyester film layer (B layer). A single 25 μm single-layer film is prepared from the resin (A) or the polyester resin (B), and a laminate material is prepared under the same conditions as in the examples and the comparative examples. TMA (TMA-SS100 manufactured by Seiko Electronics Co., Ltd.) Thus, the probe intrusion start temperature (° C.) was measured under the conditions of temperature rise conditions: 5 ° C./min, load: 3 g, probe: 1 mm flat (made of quartz).

(6) Evaluation of punch releasability The releasability of the film on the inner surface of the can and the processing punch was evaluated by randomly extracting 500 cans of continuously formed cans and observing the degree of cramping of the cans occurring at the top of the formed cans.
Evaluation of releasability was performed by setting evaluation criteria as follows.
A: Good without opening the can opening
○: A slight can opening is cramped, but a normal can height can be secured and there is no practical problem. ○ to △: Cans are cramped and it is difficult to secure a regular can height. Sporadic and impractical
Δ: The can opening is cramped and it is difficult to secure a normal can height, impractical
×: The can body does not come out of the punch, or even if it falls out, there is severe cramping in the can opening, impractical

(7) Evaluation of soundness of inner surface film of can Regarding the degree of scratching of the resin film on the inner surface of the can, the can body was made into an anode and a cathode with an electrolyte solution containing 0.1% surfactant in 1.0% saline. Was used as a copper wire, and the current value after 3 seconds was measured at an applied voltage of 5 V to evaluate the soundness of the coating film.
In addition, 50 cans were extracted at random, and the load average value is shown in Table 2.
When the metal material was a steel plate, the can inner surface film soundness was set to a practical level of 0.2 mA or less in terms of the load average value of the QTV value.
(Hereafter, this evaluation method is called QTV test)

(8) Evaluation of dent resistance of the inner film of the can Regarding the dent resistance of the film on the inner surface of the can, after filling the can with tea and performing a retort sterilization treatment at 125 ° C. for 30 minutes, it is stored in a refrigerator at 4 ° C. When the can body temperature reached 4 ° C., a wedge with a width of 20 mm with a tip width of 1 mm was placed on the can body, and a load of 500 g was dropped from a height of 5 cm onto the wedge to cause dents. (This method is called can body dent)
Similarly, when the can body temperature reached 4 ° C., the can bottom was dropped from the position of 45 cm in height at an angle of 60 ° to cause dents. (This method is called can bottom dent.)
The dent resistance was evaluated after the can body dent and the can body dent were sealed with an insulating material other than the deformed portion, the can body as an anode, the cathode as a copper wire, and a current value after 30 seconds at an applied voltage of 6V. Was measured to evaluate the soundness of the dent film. The evaluation was conducted by randomly extracting 20 cans, and the highest measured values are shown in Table 2. The dent resistance was set to a practical level of 0.03 mA or less for both the can body dent and the can body dent.
(Hereinafter, this evaluation method is referred to as dent resistance evaluation).

The abbreviations and contents of the vinyl polymers used in Examples and Comparative Examples are as follows: (1) Vinyl polymer A (polymer A): ethylene-methyl acrylate / glycidyl methacrylate polymer (2) Vinyl polymer B (polymer B): ethylene-vinyl acetate / glycidyl methacrylate polymer The contents of the heat stabilizer and the antioxidant used in the examples and comparative examples are as follows.
(1) Thermal stabilizer: bis (2,4-dicumylphenyl) pentaerythritol-di-phosphite (2) Antioxidant: tetrakis [methylene (3,5-di-t-butylhydroxyhydrocinnamate)] methane

Example 1
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of 0.5 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent sphere equivalent diameter of 730 nm, and 0.1% of a vinyl polymer. A 12 μm thick film layer having a melting point of 237 ° C. and a polyester film layer (B layer) containing 13 parts by mass of an antioxidant, 13 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 730 nm, and 3. A two-layer film (film 1) having a total thickness of 25 μm composed of a film layer having a thickness of 13 μm having a melting point of 0 part by mass of 223 ° C. was prepared.

The film 1 thus obtained and a film for the outer surface of the can, a single-layer polyester film having a melting point of 235 ° C. and a thickness of 12 μm (film A, a film necessary for molding a can described later, irrespective of Examples and Comparative Examples) Therefore, the plate thickness having a hydrated chromium oxide film of 15 mg / m ^{2 in} terms of metallic chromium on the upper layer of 550 mg / m ² as the Ni adhesion amount on one side of the steel plate is used. A 0.19 mm Ni-plated steel plate is heated with a heating roll (jacket roll), and the other steel plate is placed so that the polyester film layer (B layer) is in contact with the steel plate at a plate temperature of 250 ° C. on one side. After film A was first bonded to both sides by thermocompression bonding with a laminating roll, the steel sheet was heated at 255 ° C. for 3 seconds and then immersed in 30 ° C. water for rapid cooling. It was created polyester film laminated steel sheet (test 1).

  Similarly, as the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) comprises 0.5 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent sphere equivalent diameter of 730 nm, and a vinyl polymer. A film layer having a melting point of 245 ° C. and a thickness of 12 μm and a polyester film layer (B layer) containing 0.1 part by mass is an antioxidant, 13 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 730 nm, and a vinyl polymer. A two-layer film (film 2) having a total thickness of 25 μm composed of a film layer having a thickness of 13 μm and a melting point of 243 ° C. was prepared.

  The film 2 thus obtained and the outer film of the can as a single-layer polyester film having a melting point of 245 ° C. and a thickness of 12 μm (film B, a film necessary for molding a can described later, irrespective of the examples and comparative examples) Therefore, the Ni-plated steel sheet is heated with a heating roll (jacket roll) using a heating roll (jacket roll), and the film 2 is placed on one surface at a polyester film layer (B layer). Film B on the other steel plate surface so as to be in contact with the steel plate, and after the primary adhesion to both surfaces by a thermocompression method with a laminate roll, the steel plate temperature was subsequently heated at 265 ° C. for 3 seconds, and then 30 ° C. A polyester film-laminated steel sheet (Test 2) was prepared by immersion in water and quenching.

  Similarly, as the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) comprises 0.5 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent sphere equivalent diameter of 730 nm, and a vinyl polymer. A film layer having a melting point of 252 ° C. and a thickness of 12 μm and a polyester film layer (B layer) containing 0.1 part by mass is an antioxidant, 13 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 730 nm, and a vinyl polymer. A bilayer film (film 3) having a total thickness of 25 μm and comprising a film layer having a thickness of 13 μm and a melting point of 248 ° C. was prepared.

  Using the film 3 thus obtained and the film B, the Ni-plated steel sheet is heated with a heating roll (jacket roll), and the film temperature is 265 ° C. and the polyester film layer (B layer) is formed on one surface. The film B was first bonded to both surfaces by thermocompression bonding with a laminating roll so that the other steel plate surface was in contact with the steel plate, and then the steel plate temperature was heated at 275 ° C. for 3 seconds, followed by 30 ° C. water. A polyester film-laminated steel sheet (Test 3) was prepared by immersing the film in water. As a result of observing the dispersion state of the rubber elastic resin and the vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel plates obtained in Test 1 to Test 3, Test 1, In both Test 2 and Test 3, the rubber elastic resin was almost encapsulated with a vinyl polymer.

The cold heat of crystallization, heat of crystal melting, and glass transition temperature of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can. The details of the intrinsic viscosity, the contents of the rubber elastic resin, and the contents of the vinyl polymer are shown in Table 1, and the details of the contents of the lubricant, the antioxidant and the like are shown in Table 2.
Processing speed of 90 cans / minute so that the surface coated with the polyester film (F) becomes the inner surface side of the can after applying the forming lubricant to both surfaces of the laminated steel sheets of Test 1 to Test 3 thus obtained. Then, cup drawing, redrawing and ironing were carried out to form a 350 ml beer can-sized seamless can with a can wall portion processing degree of 58%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

  Further, the opening was trimmed so that the temperature of the metal plate of the can obtained from Test 1 was 255 ° C, and the temperature of the can obtained from Test 2 was 260 ° C. The obtained can was heated by passing through a hot stove so as to reach 275 ° C., and then immediately cooled by blowing compressed air. Next, the neck processing and the flange processing were performed so that the can lid of the designation 204 was wound and a 350 ml size can was produced. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can.

The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, it can be seen that the laminated steel sheets of Test 1 to Test 3 of Example 1 exhibit good punch releasability and are excellent in canability.
It can also be seen that the resulting can has good QTV inner surface quality and dent resistance indicating the soundness of the inner film.

    (Example 2) As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of 5 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent spherical equivalent diameter of 730 nm, and a vinyl polymer. A film layer and a polyester film layer (B layer) having a melting point of 237 ° C. containing 1.0 part by mass and a polyester film layer (B layer) are 13 parts by mass of an antioxidant, a rubber elastic resin having an equivalent spherical equivalent diameter of 730 nm, and a vinyl polymer. A two-layer film (film 4) having a total thickness of 25 μm composed of a film layer having a thickness of 13 μm and a melting point of 223 ° C. containing 3.0 parts by mass was prepared.

  Using the film 4 obtained in this way and the film A used in Example 1, the Ni-plated steel plate used in Example 1 was heated with a heating roll (jacket roll), and the film temperature was 260 ° C. on one side of the film 4. After the film A is first bonded to both surfaces by thermocompression bonding with a laminating roll so that the polyester film layer (B layer) is in contact with the steel plate, the steel plate temperature is then 265 ° C. After heating for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 4).

  Similarly, as the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of 5 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent spherical equivalent diameter of 730 nm, and a vinyl polymer of 1. A film layer having a melting point of 252 ° C. and a thickness of 12 μm and a polyester film layer (B layer) containing 0 part by mass is an antioxidant, 13 parts by mass of a rubber elastic resin having an equivalent sphere equivalent diameter of 730 nm and 3 vinyl polymers. A two-layer film (film 5) having a total thickness of 25 μm and a film layer having a thickness of 13 μm and a melting point of 248 ° C. containing 0.0 part by mass was prepared.

Using the film 5 obtained in this way and the film B used in Example 1, the Ni-plated steel plate used in Example 1 was heated with a heating roll (jacket roll), and the film temperature was 265 ° C. on one surface. After the film B is first bonded to both surfaces by thermocompression bonding with a laminate roll so that the polyester film layer (B layer) is in contact with the steel plate, the steel plate temperature is then 275 ° C. After heating for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 5).
As a result of observing the dispersion state of the rubber elastic resin and the vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel plates obtained in Test 4 and Test 5, Test 4 and In both tests 5, the rubber elastic resin was almost encapsulated with a vinyl polymer.

The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Table 1 shows details of the temperature, intrinsic viscosity, contents of the rubber elastic resin, and contents of the vinyl polymer, and Table 2 shows details of the contents of the lubricant and the antioxidant.
Processing speed of 90 cans / minute so that the surface coated with the polyester film (F) becomes the inner surface side of the can after applying the forming lubricant on both surfaces of the laminated steel sheets of Test 4 and Test 5 thus obtained. Then, cup drawing, redrawing and ironing were carried out to form a 350 ml beer can-sized seamless can with a can wall portion processing degree of 58%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

  Further, the opening was trimmed so that the temperature of the metal plate of the can obtained from Test 4 was 255 ° C., and the temperature of the can obtained from Test 5 was 275 ° C. After passing through and heated, it was immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can.

  The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated steel sheet of Test 4 of Example 2 is slightly inferior to the laminated steel sheet obtained from Test 1 of Example 1 but has a level of practicality. is there. In addition, it can be seen that the laminated steel sheet of Test 5 exhibits good punch releasability and is excellent in can manufacturing ability. It can also be seen that the cans obtained from Test 4 and Test 5 have good QTV values indicating the soundness of the inner film and good dent resistance.

(Example 3)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of 7 parts by mass of a lubricant, an antioxidant, a heat stabilizer, a rubber elastic resin having an equivalent sphere equivalent diameter of 280 nm, and a vinyl polymer. The film layer and polyester film layer (B layer) having a melting point of 248 ° C. and a thickness of 12 μm are composed of 15 parts by mass of a heat stabilizer, an antioxidant, and a rubber elastic resin having an equivalent spherical equivalent diameter of 280 nm. A bilayer film (film 6) having a total thickness of 25 μm, comprising a film layer having a thickness of 13 μm and a melting point of 248 ° C., containing 3.0 parts by weight of a vinyl polymer.

  Using the film 6 thus obtained and the film B used in Example 1, the Ni-plated steel plate used in Example 1 was heated with a heating roll (jacket roll), and the film temperature was 265 ° C. and the film 6 on one surface. The film B is first bonded to both surfaces by thermocompression bonding with a laminate roll so that the polyester film layer (B layer) is in contact with the steel plate, and then the steel plate temperature is 265 ° C. After heating for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 6).

A 3004 series aluminum alloy sheet having a thickness of 0.28 mm, which is subjected to a chromium phosphate chemical conversion treatment having a coating amount of 12 mg / m ^{2 in} terms of metallic chromium on one side, using the film 6 and the film B. Is heated with a heating roll (jacket roll), the plate temperature is 265 ° C., and the other aluminum alloy plate surface is attached to the film 6 on one side so that the polyester film layer (B layer) is in contact with the aluminum alloy plate. After the film B was primarily bonded to both sides, the aluminum alloy plate was heated at 265 ° C. for 3 seconds and then immersed in water at 30 ° C. to rapidly cool to prepare a polyester film laminated aluminum alloy plate (Test 7). .

Dispersion of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel sheet obtained in Test 6 and the laminated aluminum alloy plate obtained in Test 7 As a result of observing the state, in both Test 6 and Test 7, the rubber elastic resin was almost encapsulated with a vinyl polymer.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Table 1 shows details of the temperature, intrinsic viscosity, contents of the rubber elastic resin, and contents of the vinyl polymer, and Table 2 shows details of the contents of the lubricant, antioxidant, heat stabilizer and the like.

  After applying the forming lubricant to both sides of the laminated steel plate of test 6 and the laminated aluminum alloy plate of test 7 thus obtained, test 6 is performed so that the surface coated with the polyester film (F) becomes the inner surface side of the can. The laminated steel sheet of No.1 is a 350ml size seamless can with 55% processing of the can wall by cup drawing, redrawing and ironing at a processing speed of 80 cans / min. The plate was subjected to cup drawing, redrawing and ironing at a processing rate of 100 cans / minute to form 350 ml beer can-sized seamless cans each having a processing degree of the can wall portion of 62%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

  Further, the opening is trimmed, and the can obtained from Test 6 and Test 7 is heated in a hot air oven so that the plate temperature is 265 ° C. Sprayed and cooled quickly. Next, neck processing and flange processing were performed according to the procedure of Example 1 to prepare a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can.

  The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, both the laminated steel plate of test 6 and the laminated alloy plate of test 7 of Example 3 are slightly inferior in punch releasability, but are at a level where they have practicality, and can manufacturing performance It turns out that there is no problem. It can also be seen that the cans obtained from Test 6 and Test 7 have good QTV values indicating the soundness of the inner surface film and good dent resistance.

Example 4
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of a lubricant, an antioxidant, a heat stabilizer, 7 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 1770 nm and a vinyl polymer. A film layer having a melting point of 248 ° C. and a polyester film layer (B layer) containing 1.5 parts by mass is 15 parts by mass of a heat stabilizer, an antioxidant, and a rubber elastic resin having an equivalent sphere equivalent diameter of 1770 nm. And a bilayer film (film 7) having a total thickness of 25 μm composed of a film layer having a melting point of 248 ° C. and a thickness of 13 μm, containing 3.0 parts by mass of the vinyl polymer.

Using the film 7 thus obtained and the film B used in Example 1, the steel plate has a hydrated chromium oxide film of 110 mg / m ^{2 on} both sides of the steel plate and 18 mg / m ^{2 in} terms of metal chromium on the upper layer. An electrolytic chromic acid treated steel plate (TFS-CT) having a thickness of 0.19 mm is heated with a heating roll (jacket roll), the plate temperature is 265 ° C., and the polyester film layer (B layer) is a steel plate on one surface. Film B on the other steel plate surface so as to be in contact with each other, and firstly bonded to both surfaces by a thermocompression bonding method with a laminate roll, and subsequently the steel plate temperature was heated at 265 ° C. for 3 seconds and then into 30 ° C. water. Immersed and rapidly cooled, a polyester film laminated steel sheet (Test 8) was prepared.
As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel plate obtained in Test 8, the rubber elasticity of Test 8 was observed. The resin was almost encapsulated with a vinyl polymer.

The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Table 1 shows details of the temperature, intrinsic viscosity, contents of the rubber elastic resin, and contents of the vinyl polymer, and Table 2 shows details of the contents of the lubricant, antioxidant, heat stabilizer and the like.
After applying the forming lubricant to both sides of the laminated steel sheet of test 8 obtained in this way, cup drawing is performed at a processing speed of 80 cans / minute so that the surface coated with the polyester film (F) becomes the inner surface side of the can. Then, redrawing and ironing were performed to form a 350 ml beer can-sized seamless can having a can wall processing degree of 55%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

  Further, the opening was trimmed and heated through a hot air oven so that the temperature of the metal plate of the can was 265 ° C., and then immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to prepare a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can. The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated steel sheet of Test 8 of Example 4 is slightly inferior in punch releasability, but is at a level where it has practicality, and it can be seen that there is no problem in can-making ability. Further, it can be seen that the can obtained from Test 8 has good QTV value indicating the soundness of the inner surface film and good dent resistance.

(Example 5)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of 2 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent spherical equivalent diameter of 860 nm, and 0.5 mass of a vinyl polymer. The film layer having a melting point of 248 ° C. and a thickness of 8 μm and the polyester film layer (B layer) are 7 parts by mass of an antioxidant, a rubber elastic resin having an equivalent spherical equivalent diameter of 860 nm, and 1.5% of the vinyl polymer. A two-layer film (film 8) having a total thickness of 25 μm composed of a film layer having a melting point of 237 ° C. and a thickness of 17 μm was prepared.

  Similarly, as the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of a lubricant, an antioxidant, 2 parts by mass of a rubber elastic resin having an equivalent sphere equivalent diameter of 860 nm, and 0% of a vinyl polymer. 5 parts by mass of a film layer having a melting point of 248 ° C. and a thickness of 8 μm, a polyester film layer (B layer), an antioxidant, 35 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 860 nm, and a vinyl polymer A two-layer film (film 9) having a total thickness of 25 μm composed of a film layer having a melting point of 237 ° C. and a thickness of 17 μm was prepared.

Using the film 8 obtained in this way and the film B used in Example 1, after performing Ni plating of 550 mg / m ² as the amount of adhesion on one side of the steel sheet, a chemical conversion treatment containing a phenol resin and condensed phosphoric acid The Ni-chemical conversion treated steel sheet applied with the liquid and dried and subjected to a chemical conversion treatment of 10 mg / m ² as the C adhesion amount on one side was heated with a heating roll (jacket roll) according to the procedure of Example 1, and the plate temperature was 265. After the film 8 is adhered to one side at a temperature of 1 ° C., the film B is adhered to the other side of the steel sheet with a laminate roll by a thermocompression bonding method so that the polyester film layer (B layer) is in contact with the steel sheet. The steel sheet was heated at 265 ° C. for 3 seconds and then immersed in water at 30 ° C. to rapidly cool to prepare a polyester film laminated steel sheet (Test 9).

  Similarly, using the film 9 and the film B used in Example 1, the Ni-chemically treated steel plate was heated with a heating roll (jacket roll), and the film temperature was 265 ° C., and the film 9 was polyester on one side. After the film B (layer B) is in contact with the steel plate, the film B is first bonded to both surfaces by thermocompression bonding with a laminating roll, and then the steel plate temperature is 265 ° C. for 3 seconds. After heating, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 10).

As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (B layer) of the laminated steel sheets obtained in Test 9 and Test 10, both Test 9 and Test 10 were rubber elastic. The resin was almost encapsulated with a vinyl polymer.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can The details of temperature, intrinsic viscosity, rubber elastic resin content, and vinyl polymer content are shown in Table 1, and details of the contents of the lubricant, antioxidant, etc. are shown in Table 2.

Processing speed of 90 cans / minute so that the surface coated with the polyester film (F) becomes the inner surface side of the can after applying the forming lubricant to both sides of the laminated steel sheets of Test 9 and Test 10 thus obtained. Then, cup drawing processing, redrawing processing and ironing processing were performed to form 350 ml beer can-sized seamless cans each having a processing degree of the can wall portion of 58%.
About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

Further, the opening was trimmed and heated by passing through a hot air oven so that the metal plate temperature of the can was 265 ° C., and then immediately cooled by blowing compressed air. Next, 204 necking and flanging were performed according to the procedure of Example 1 to produce a 350 ml can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can.
The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2.

  As can be seen from Table 2, the laminated steel plate of Test 9 of Example 5 has good punch release properties, and the laminated steel plate of Test 10 was slightly inferior in punch release properties, but has practicality. It can be seen that there is no problem with can-making performance. In addition, the cans obtained from Test 9 and Test 10 had practical levels of QTV value and dent resistance indicating the soundness of the inner film, and the cans obtained from Test 10 were particularly excellent in dent resistance.

(Example 6)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of 7 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent sphere equivalent diameter of 850 nm, and 1.5 parts by mass of a vinyl polymer. The film layer and the polyester film layer (B layer) having a melting point of 245 ° C. and a thickness of 10 μm are 10 parts by mass of an antioxidant, a rubber elastic resin having an equivalent spherical equivalent diameter of 850 nm, and 2.0 mass of the vinyl polymer. A two-layer film (film 10) having a total thickness of 25 μm composed of a film layer having a melting point of 222 ° C./237° C. and a thickness of 15 μm was prepared.

  Using the film 10 thus obtained and the film B used in Example 1, the electrolytic chromic acid treated steel plate (TFS-CT) used in Example 4 was heated with a heating roll (jacket roll), and the plate temperature was 255 ° C. The film 10 used in Example 1 was applied to the other steel sheet surface by a thermocompression bonding method with a laminate roll so that the polyester film layer (B layer) was in contact with the steel sheet on one surface. After bonding, the steel sheet was subsequently heated at 260 ° C. for 3 seconds, then immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 11).

As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel plate obtained in Test 11, the rubber elasticity of Test 11 was observed. The resin was almost encapsulated with a vinyl polymer.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can The details of temperature, intrinsic viscosity, rubber elastic resin content and vinyl polymer content are shown in Table 1, and details of the lubricant and antioxidant content are shown in Table 2.

  After applying the forming lubricant to both sides of the laminated steel sheet of Test 11 thus obtained, cup squeezing was performed at a processing speed of 80 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Processing, redrawing and ironing were performed to form a 350 ml beer can-size seamless can with a can wall processing degree of 58%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

  Further, the opening was trimmed, and heated through a hot air oven so that the metal plate temperature of the can was 260 ° C., and then immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can. The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated steel sheet of Test 11 of Example 6 is slightly inferior in punch releasability, but has practicality, and it can be seen that there is no problem in can-making ability. Further, it can be seen that the can obtained from the test 11 has a good QTV value indicating the soundness of the inner film and dent resistance.

(Example 7)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of a lubricant, a heat stabilizer, 5 parts by mass of a rubber elastic resin having an equivalent sphere equivalent diameter of 780 nm and 1.0% of a vinyl polymer. The film layer and the polyester film layer (B layer) having a melting point of 248 ° C. and a thickness of 5 μm include 13 parts by mass of a rubber stabilizer having an equivalent spherical equivalent diameter of 750 nm and a vinyl polymer. A two-layer film (film 11) having a total thickness of 12 μm composed of a film layer having a thickness of 7 μm and a melting point of 237 ° C. was prepared.

  Similarly, as the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of a lubricant, a heat stabilizer, 5 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 780 nm, and 1 vinyl polymer. The film layer and polyester film layer (B layer) having a melting point of 248 ° C. and a thickness of 15 μm are comprised of 13 parts by mass of a rubber stabilizer with an equivalent spherical equivalent diameter of 750 nm and a vinyl polymer. A two-layer film (film 12) having a total thickness of 38 μm and comprising a film layer having a thickness of 23 μm and a melting point of 237 ° C. containing 3.0 parts by mass was prepared.

  Using the film 11 thus obtained and the film B used in Example 1, the Ni plating used in Example 1 was heated with a heating roll (jacket roll), and the film temperature was 260 ° C. on one side. No. 11 is bonded to the other steel sheet surface by a thermocompression bonding method on both surfaces so that the polyester film layer (B layer) is in contact with the steel sheet, and then the steel sheet temperature is 265 ° C. After being heated for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 12).

  Similarly, using the film 12 and the film B used in Example 1, the Ni-plated steel plate used in Example 1 is heated with a heating roll (jacket roll), the plate temperature is 260 ° C., and the film is formed on one surface. No. 12 is attached to the other steel sheet surface by a thermocompression bonding method so that the polyester film layer (B layer) is in contact with the steel sheet, and then the steel sheet temperature is 265 ° C. After being heated for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 13).

As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel sheets obtained in Test 12 and Test 13, Test 12 In both Tests 13 and 13, the elastic rubber resin was almost encapsulated with a vinyl polymer.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Details of temperature, intrinsic viscosity, rubber elastic resin content and vinyl polymer content are shown in Table 1, and details of the lubricant and heat stabilizer content are shown in Table 2.

  Processing speed of 80 cans / minute so that the surface coated with the polyester film (F) becomes the inner surface side of the can after applying the forming lubricant to both surfaces of the laminated steel sheets of Test 12 and Test 13 thus obtained. Then, cup drawing, redrawing and ironing were carried out to form a 350 ml beer can-sized seamless can with a can wall portion processing degree of 58%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

  Further, the opening was trimmed, and heated through a hot air oven so that the metal plate temperature of the can was 260 ° C., and then immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can. The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2.

  As can be seen from Table 2, the laminated steel sheet of Test 12 of Example 7 showed good punch release properties. In addition, the laminated steel sheet of Test 13 is slightly inferior in punch releasability, but it has practicality, and it can be seen that there is no problem in can manufacturing. Further, the cans obtained from Test 12 and Test 13 had practical levels of QTV value and dent resistance indicating the soundness of the inner film, and the cans obtained from Test 13 were particularly excellent in dent resistance.

(Example 8)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of a lubricant, an antioxidant, a thermal stabilizer, 10 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 920 nm, and a vinyl polymer. The film layer and the polyester film layer (B layer) having a melting point of 255 ° C. and a melting point of 255 μm are 13 parts by weight of an antioxidant, a heat stabilizer, and a rubber elastic resin having an equivalent spherical equivalent diameter of 920 nm. A bilayer film (film 13) having a total thickness of 25 μm composed of a film layer having a thickness of 13 μm and a melting point of 222 ° C./244° C. containing 3.0 parts by weight of a vinyl polymer was prepared.

  Using the film 13 obtained in this way and the film B used in Example 1, the aluminum alloy plate used in Example 3 was heated with a heating roll (jacket roll), the film temperature was 260 ° C., and the film 13 on one surface. The film B is first bonded to both surfaces by thermocompression bonding with a laminate roll so that the polyester film layer (B layer) is in contact with the aluminum alloy plate, and then the aluminum alloy plate The plate temperature was heated at 275 ° C. for 3 seconds, then immersed in 30 ° C. water and quenched to prepare a polyester film laminated aluminum alloy plate (Test 14).

As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated aluminum alloy plate obtained in Test 14, The rubber elastic resin was almost encapsulated with a vinyl polymer.
Heat of cold crystallization and heat of crystal melting of the polyester film layer (A layer) and the polyester film layer (B layer) of the polyester film (F) coated on the surface of the laminated aluminum alloy plate corresponding to the inner surface side of the can Table 1 shows the details of the glass transition temperature, intrinsic viscosity, rubber elastic resin content, vinyl polymer content, and Table 2 shows the details of the lubricant, antioxidant, heat stabilizer, etc. It was.

After applying a molding lubricant on both surfaces of the laminated aluminum alloy plate of Test 14 thus obtained, the processing speed was 100 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Cup drawing, redrawing and ironing were performed to form a 350 ml beer can-sized seamless can with a can wall processing degree of 62%.
About the obtained shaping | molding can, the mold release property of the punch of an internal film was investigated. The results are shown in Table 2.

  Further, the opening was trimmed and heated through a hot air oven so that the metal plate temperature of the can was 275 ° C., and then immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can. The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated aluminum alloy plate of Test 14 of Example 8 is slightly inferior in punch releasability, but has practicality, and it can be seen that there is no problem in can manufacturing. . In addition, the can obtained from Test 14 had a QTV value indicating the soundness of the inner film at a practical level, and was particularly excellent in dent resistance.

(Comparative Example 1)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of a lubricant, an antioxidant, a heat-stabilized rubber elastic resin having an equivalent sphere equivalent diameter of 780 nm and 0.5 parts by weight of vinyl resin. A 12 μm thick film layer having a melting point of 232 ° C. containing 0.1 part by mass and a polyester film layer (B layer) are made of an antioxidant, a heat stabilizer, and a rubber elastic resin having an equivalent spherical equivalent diameter of 780 nm. A bilayer film (film 14) having a total thickness of 25 μm and comprising a film layer having a thickness of 13 μm and a melting point of 218 ° C. containing 7 parts by mass and 1.5 parts by mass of a vinyl polymer was prepared.

  Using the film 14 thus obtained and the film A used in Example 1, the Ni-plated steel plate used in Example 1 was heated with a heating roll (jacket roll), and the film temperature was 250 ° C. on one surface. After the film A is first bonded to both surfaces by thermocompression bonding with a laminating roll so that the polyester film layer (B layer) is in contact with the steel plate, the steel plate temperature is then 265 ° C. After heating for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 15). As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (B layer) of the laminated steel sheet obtained in Test 15, the rubber elastic resin of Test 15 is almost a capsule made of vinyl polymer. It was converted.

  The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Table 1 shows details of temperature, intrinsic viscosity, contents of rubber elastic resin, and contents of vinyl polymer, and Table 2 shows details of contents of lubricant, antioxidant, and heat stabilizer. After applying the forming lubricant on both sides of the laminated steel sheet of Test 15 thus obtained, cup squeezing was performed at a processing speed of 80 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Processing, redrawing processing, and ironing processing were performed to form a 350 ml beer can-sized seal can with a processing degree of the can wall portion of 65%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

  Molded cans were cramped at the opening of the can, and it was difficult to ensure the correct can height. After trimming, the metal plate temperature of the can was heated by passing through a hot air oven so that the plate temperature was 265 ° C., and then immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can.

  The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated steel plate of Test 15 of Comparative Example 1 is inferior in punch releasability, so that the can opening is buckled, and it is difficult to ensure a normal can height. Are sporadic and not at the practical level. In addition, the can obtained from Test 15 has punch scratches that occur when the inner film has poor punch releasability, and the QTV value indicating the soundness of the inner film is higher than that of the Examples, and is at a practical level. Absent. However, the dent resistance was at a practical level with no difference from the examples.

(Comparative Example 2)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of a lubricant, an antioxidant, a heat stabilizer, 7 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 670 nm, and a vinyl polymer. The film layer and the polyester film layer (B layer) having a melting point of 251 ° C. and a thickness of 12 μm are 3 parts by weight of an antioxidant, a heat stabilizer, and a rubber elastic resin having an equivalent spherical equivalent diameter of 650 nm. A bilayer film (film 15) having a total thickness of 25 μm and a film layer having a thickness of 13 μm and a melting point of 237 ° C. containing 0.7 part by weight of the vinyl polymer was prepared.

  Using the film 15 thus obtained and the film B used in Example 1, the Ni-plated steel plate used in Example 1 was heated with a heating roll (jacket roll), and the film temperature was 260 ° C. on one surface. The film B is first bonded to both surfaces by thermocompression bonding with a laminate roll so that the polyester film layer (B layer) is in contact with the steel plate, and then the steel plate temperature is 265 ° C. After heating for 3 seconds, it was immersed in water at 30 ° C. and quenched to prepare a polyester film laminated steel sheet (Test 16).

  As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel sheet obtained in Test 16, the rubber elasticity of Test 16 was observed. The resin was almost encapsulated with a vinyl polymer. The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Table 1 shows details of temperature, intrinsic viscosity, contents of rubber elastic resin, and contents of vinyl polymer, and Table 2 shows details of contents of lubricant, antioxidant, and heat stabilizer.

  After applying the forming lubricant to both sides of the laminated steel sheet of Test 16 thus obtained, cup squeezing was performed at a processing speed of 80 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Processing, redrawing processing, and ironing processing were performed to form a 350 ml beer can-size seamless can with a can wall processing degree of 55%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

  Further, the opening was trimmed and heated by passing through a hot air oven so that the metal plate temperature of the can was 265 ° C., and then immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can. The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated steel plate of Test 16 of Comparative Example 2 was slightly inferior in punch releasability but at a practical level, and there was no problem in can manufacturing. However, the can obtained from Test 16 has a QTV value indicating the soundness of the inner film, which is not different from that in Example 1 and is at a practical level, but its dent resistance is inferior to that in Example and is at a practical level. There wasn't.

(Comparative Example 3)
As the polyester film (F) for the inner surface of the can, the polyester raw material used in Test 3 of Example 1 was used. The polyester film layer (A layer) was 7 masses of a lubricant and a rubber elastic resin having an equivalent spherical equivalent diameter of 670 nm. Part and a vinyl polymer containing 1.5 parts by mass, a film layer having a melting point of 251 ° C. and having a thickness of 12 μm and no antioxidant and heat stabilizer, and a polyester film layer (B layer) have an equivalent spherical equivalent diameter of 650 nm Two layers of a total thickness of 25 μm comprising a film layer containing 15 parts by weight of a rubber elastic resin and 3.0 parts by weight of a vinyl polymer, a melting point of 248 ° C., a 13 μm-thick antioxidant and a heat stabilizer. A film (film 16) was prepared.

  Using the film 16 thus obtained and the film B used in Example 1, the Ni-plated steel plate used in Example 1 was heated with a heating roll (jacket roll), and the film temperature was 260 ° C. on one surface. The film B is first bonded to both surfaces by thermocompression bonding with a laminate roll so that the polyester film layer (B layer) is in contact with the steel plate, and then the steel plate temperature is 265 ° C. After heating for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 17).

  As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel plate obtained in Test 17, the rubber elasticity of Test 17 was observed. The resin was almost encapsulated with a vinyl polymer. The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Details of temperature, intrinsic viscosity, rubber elastic resin content and vinyl polymer content are shown in Table 1, and details of lubricant content are shown in Table 2.

  After applying the forming lubricant to both surfaces of the laminated steel sheet of Test 17 thus obtained, cup squeezing was performed at a processing speed of 80 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Processing, redrawing processing, and ironing processing were performed to form a 350 ml beer can-size seamless can with a can wall processing degree of 55%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.

Further, the opening was trimmed, and heated through a hot air oven so that the metal plate temperature of the can was 260 ° C., and then immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to prepare a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can. The QTV test and dent resistance of the regular can inner film obtained in this way were examined. The results are shown in Table 2.
As can be seen from Table 2, the laminated steel sheet of Test 17 of Comparative Example 3 was slightly inferior in punch releasability but at a practical level, and there was no problem in can manufacturing. However, the can obtained from Test 17 has a QTV value indicating the soundness of the inner film at a practical level with no difference compared to the Examples, but the dent resistance is inferior to the Examples and not at the practical level. It was.

(Comparative Example 4)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of a lubricant, an antioxidant, a heat stabilizer, 12 parts by mass of a rubber elastic resin having an equivalent sphere equivalent diameter of 2250 nm and a vinyl weight. A 12 μm thick film layer and a polyester film layer (B layer) containing 2.5 parts by mass of the melting point and having a melting point of 255 ° C. are made of an antioxidant, a heat stabilizer, and a rubber elastic resin having an equivalent spherical equivalent diameter of 2250 nm. A bilayer film (film 17) having a total thickness of 25 μm composed of a film layer having a thickness of 13 μm and a melting point of 248 ° C. containing 3.0 parts by mass of the vinyl polymer was prepared.

  Using the film 17 thus obtained and the film B used in Example 1, the electrolytic chromic acid-treated steel plate used in Example 4 was heated with a heating roll (jacket roll), and the plate temperature was 265 ° C. on one side. The film 17 is primarily bonded to both surfaces by thermocompression bonding with a laminating roll so that the polyester film layer (B layer) is in contact with the steel plate, and then the steel plate temperature is 280. After heating at 30 ° C. for 3 seconds, it was immersed in water at 30 ° C. and quenched to prepare a polyester film laminated steel sheet (Test 18).

As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel plate obtained in Test 18, the rubber elasticity of Test 18 was observed. The resin was almost encapsulated with a vinyl polymer.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Details of temperature, intrinsic viscosity, rubber elastic resin content and vinyl polymer content are shown in Table 1, and details of lubricant content are shown in Table 2.

After applying the forming lubricant to both surfaces of the laminated steel sheet of Test 17 thus obtained, cup squeezing was performed at a processing speed of 80 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Processing, redrawing processing, and ironing processing were performed to form a 350 ml beer can-size seamless can with a can wall processing degree of 55%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2.
The laminated steel sheet of Test 18 of Comparative Example 4 has a remarkably inferior punch releasability, and the punch does not come out of the can body. There is a problem in can characteristics.

  However, after trimming the can with its opening cramped and removing the buckle just in case, after passing through the hot air furnace and heating so that the metal plate temperature of the can is 280 ° C. Immediately after that, it was quenched by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to create a can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can. Only the dent resistance at the bottom of the can was examined for the inner surface film of the can thus obtained. The results are shown in Table 2. As can be seen from Table 2, the dent resistance at the bottom of the can was inferior to that of the example and was not at a practical level. In order to investigate this cause, as a result of observing the dispersion state of the rubber elastic resin in the dent film, it was found that the impact failure of the polyester resin propagated and the rubber elastic resin was also broken due to the occurrence of fine cracks. . Further, as described above, the releasability of the punch was extremely inferior.

(Comparative Example 5)
As a polyester film (F) for the inner surface of the can, the polyester film layer (A layer) comprises 0.3% by mass of a lubricant having a particle size of 0.2 μm, an antioxidant, and a melting point of 248 ° C. and a thickness of 12 μm. A film layer not containing a rubber elastic resin and a vinyl polymer, and a polyester film layer (B layer) are an antioxidant, a heat stabilizer, 10 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 750 nm, and a vinyl polymer. A bilayer film (film 18) having a total thickness of 25 μm composed of a film layer having a melting point of 248 ° C. and a thickness of 13 μm was prepared.

  Using the film 18 thus obtained and the film B used in Example 1, the aluminum alloy plate used in Example 3 was heated with a heating roll (jacket roll), the film temperature was 260 ° C., and the film 18 was formed on one surface. The film B is first bonded to both surfaces by thermocompression bonding with a laminate roll so that the polyester film layer (B layer) is in contact with the steel plate, and then the aluminum alloy plate temperature is 265. After heating at 30 ° C. for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated aluminum alloy plate (Test 19).

As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (B layer) of the aluminum alloy plate obtained in Test 19, the rubber elastic resin of Test 19 was almost a vinyl polymer. It was encapsulated.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Table 1 shows details of temperature, intrinsic viscosity, contents of rubber elastic resin, and contents of vinyl polymer, and Table 2 shows details of contents of lubricant, antioxidant, and heat stabilizer.

After applying a molding lubricant on both surfaces of the laminated aluminum alloy plate of Test 19 thus obtained, the processing speed was 100 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Cup drawing, redrawing and ironing were performed to form a 350 ml beer can-sized seamless can with a can wall processing degree of 62%. About the obtained shaping | molding can, the mold release property of the punch of an internal film was investigated. The results are shown in Table 2.
Molded cans were cramped at the can opening, and cans in which it was difficult to ensure the normal can height were sporadic, which was not at a practical level in terms of productivity.

  However, after extracting only the can that can obtain the normal can height, trimming the opening, after passing through the hot air oven and heating so that the metal plate temperature of the can is 265 ° C. Immediately after that, it was quenched by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to prepare a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can.

The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated aluminum alloy plate of Test 19 of Comparative Example 5 has poor punch releasability as described above, so that the can opening is buckled and the proper can height is secured. Cans that are difficult to scatter are sporadic and are not at a practical level.
In addition, the can obtained from Test 19 has punch scratches that occur when the inner film has poor punch releasability, and the QTV value indicating the soundness of the inner film is higher than that of the Examples, and is at a practical level. Absent. However, the dent resistance was at a practical level with no difference from the examples.

(Comparative Example 6)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) comprises 5 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent sphere equivalent diameter of 780 nm, and 1.0 mass of a vinyl polymer. A film layer having a melting point of 248 ° C. and a thickness of 4 μm, a polyester film layer (B layer), 15 parts by mass of an antioxidant, a heat stabilizer, a rubber elastic resin having an equivalent spherical equivalent diameter of 750 nm, and vinyl A bilayer film (film 19) having a total thickness of 8 μm, comprising a film layer having a melting point of 237 ° C. and a thickness of 4 μm, containing 3.0 parts by mass of the polymer was prepared.

  Using the film 19 thus obtained and the film B used in Example 1, the electrolytic chromic acid-treated steel plate used in Example 4 was heated with a heating roll (jacket roll), and the plate temperature was 260 ° C. on one side. The film 19 is primarily bonded to both surfaces by thermocompression bonding with a laminate roll, and then the steel plate temperature is 265 ° C. so that the polyester film layer (B layer) is in contact with the steel plate. After being heated for 3 seconds, it was immersed in 30 ° C. water and rapidly cooled to prepare a polyester film laminated steel sheet (Test 20).

As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel plate obtained in Test 20, the rubber elasticity of Test 20 was observed. The resin was almost encapsulated with a vinyl polymer.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Details of temperature, intrinsic viscosity, rubber elastic resin content, and vinyl polymer content are shown in Table 1, and details of the lubricant content are shown in Table 2.

  After applying the forming lubricant to both sides of the laminated steel plate of Test 20 thus obtained, cup squeezing was performed at a processing speed of 80 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Processing, redrawing processing, and ironing processing were performed to form a 350 ml beer can-size seamless can with a can wall processing degree of 55%. About the obtained shaping | molding can, the mold release property of the inner surface film was investigated. The results are shown in Table 2.

  Further, the opening was trimmed and heated by passing through a hot air oven so that the metal plate temperature of the can was 265 ° C., and then immediately cooled by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can. The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated steel plate of Test 20 of Comparative Example 6 has good punch releasability and no problem in can making. However, the can obtained from Test 20 was inferior to the Examples in terms of QTV value and dent resistance, which showed soundness due to the thin inner film, and was not at a practical level.

(Comparative Example 7)
As the polyester film (F) for the inner surface of the can, the polyester film layer (A layer) is composed of 5 parts by mass of a lubricant, an antioxidant, a rubber elastic resin having an equivalent sphere equivalent diameter of 780 nm, and 1.0 part by mass of a vinyl polymer. Including a 15 μm thick film layer having a melting point of 248 ° C. and a polyester film layer (B layer) are 15 parts by mass of an antioxidant, a heat stabilizer, a rubber elastic resin having an equivalent spherical equivalent diameter of 750 nm, and a vinyl polymer. A two-layer film (film 20) having a total thickness of 45 μm composed of a film layer having a melting point of 237 ° C. and a thickness of 30 μm was prepared.

  Using the film 20 thus obtained and the film B used in Example 1, the Ni-plated steel plate used in Example 1 was heated with a heating roll (jacket roll), and the film temperature was 260 ° C. on one surface. The film B is first bonded to both surfaces by thermocompression bonding with a laminate roll so that the polyester film layer (B layer) is in contact with the steel plate, and then the steel plate temperature is 265 ° C. After heating for 3 seconds, it was immersed in 30 ° C. water and quenched to prepare a polyester film laminated steel sheet (Test 21).

As a result of observing the dispersion state of the rubber elastic resin and the vinyl polymer contained in the polyester film layer (A layer) and the polyester film layer (B layer) of the laminated steel plate obtained in Test 21, the rubber elasticity of Test 21 was observed. The resin was almost encapsulated with a vinyl polymer.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Details of temperature, intrinsic viscosity, rubber elastic resin content and vinyl polymer content are shown in Table 1, and details of lubricant content are shown in Table 2.

  After applying the forming lubricant on both sides of the laminated steel sheet of Test 21 obtained in this way, cup squeezing was performed at a processing speed of 80 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Processing, redrawing processing, and ironing processing were performed to form a 350 ml beer can-size seamless can with a can wall processing degree of 55%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2. Molded cans were cramped at the opening of the can, and it was difficult to ensure the normal can height.

  However, after extracting only the can that can obtain the normal can height, trimming the opening, after passing through the hot air oven and heating so that the metal plate temperature of the can is 265 ° C. Immediately after that, it was quenched by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can.

  As can be seen from Table 2, the laminated steel sheet of Test 21 of Comparative Example 7 is inferior in punch releasability as described above, so that the can opening is buckled and the proper can height is secured. Cans in difficult situations are sporadic and not at a practical level. In addition, the can obtained from Test 21 had punch scratches that occurred when the inner film had poor punch releasability, and the QTV value indicating the soundness of the inner film was slightly higher than that of the Examples, but at a practical level. There was. Further, the dent resistance was good.

(Comparative Example 8)
As polyester film for inner surface of can (F), polyester film layer (A layer) is a rubber elastic resin and vinyl polymer having a melting point of 248 ° C. and a thickness of 6 μm including a lubricant, an antioxidant and a heat stabilizer. The film layer and the polyester film layer (B layer) not containing an antioxidant, a heat stabilizer, 43 parts by mass of a rubber elastic resin having an equivalent spherical equivalent diameter of 750 nm and 10.0 parts by mass of a vinyl polymer, A two-layer film (film 21) having a total thickness of 12 μm composed of a film layer having a melting point of 237 ° C. and a thickness of 6 μm was prepared.

  Using the film 21 obtained in this way and the film B used in Example 1, the aluminum alloy plate used in Example 3 was heated with a heating roll (jacket roll), the film temperature was 260 ° C., and the film 18 on one surface. After the film B is primarily bonded to both surfaces by thermocompression bonding with a laminate roll so that the polyester film layer (B layer) is in contact with the aluminum alloy plate, the temperature of the aluminum alloy plate is subsequently increased. Was heated at 265 ° C. for 3 seconds and then immersed in water at 30 ° C. for rapid cooling to prepare a polyester film laminated aluminum alloy plate (Test 22).

As a result of observing the dispersion state of the rubber elastic resin and vinyl polymer contained in the polyester film layer (B layer) of the aluminum alloy plate obtained in Test 22, the rubber elastic resin of Test 22 was almost a vinyl polymer. It was encapsulated.
The heat of cold crystallization, heat of crystal melting, and glass transition of the polyester film layer (A layer) and polyester film layer (B layer) of the polyester film (F) coated on the steel plate surface corresponding to the inner surface side of the can Table 1 shows details of temperature, intrinsic viscosity, contents of rubber elastic resin, and contents of vinyl polymer, and Table 2 shows details of contents of lubricant, antioxidant, and heat stabilizer.

  After applying a molding lubricant on both surfaces of the laminated aluminum alloy plate of test 22 thus obtained, the processing speed was 100 cans / minute so that the surface coated with the polyester film (F) became the inner surface side of the can. Cup drawing, redrawing and ironing were performed to form a 350 ml beer can-sized seamless can with a can wall processing degree of 62%. About the obtained shaping | molding can, the mold release property of the punch of an inner surface film was investigated. The results are shown in Table 2. Molded cans were cramped at the opening of the can, and it was difficult to ensure the normal can height.

  However, after extracting only the can that can obtain the normal can height, trimming the opening, after passing through the hot air oven and heating so that the metal plate temperature of the can is 265 ° C. Immediately after that, it was quenched by blowing compressed air. Next, neck processing and flange processing were performed according to the procedure of Example 1 to produce a 350 ml size can. Table 2 shows the measurement results of the density of the inner surface side film of the obtained can.

The QTV test and dent resistance of the inner surface film of the can thus obtained were examined. The results are shown in Table 2. As can be seen from Table 2, the laminated aluminum alloy plate of Test 22 of Comparative Example 8 is inferior in punch releasability as described above, so that the can opening is buckled and the proper can height is secured. Cans that are difficult to scatter are sporadic and are not at a practical level.
However, the can obtained from the test 22 is at a practical level with no difference in QTV value indicating the soundness of the inner film from the examples. Moreover, the dent resistance was excellent.

(Comparative Example 9)
After trimming the opening using a 350 ml sized seamless can with 58% processing of the can wall obtained from Test 2 of Example 1, the can body was placed in a hot stove so that the plate temperature would be 240 ° C. After passing through and heating and then rapidly cooling with compressed air, necking and flanging were performed according to the procedure of Example 1 to produce a 350 ml can (test 23).
Similarly, after trimming the opening using a 350 ml size seamless can with a working degree of the can wall obtained from Test 5 of Example 2 of 58%, hot air is applied so that the plate temperature becomes 245 ° C. After passing through the furnace and heating and then air cooling, necking and flanging were performed according to the procedure of Example 1 to produce a 350 ml can (test 24).

  Both the obtained metal can of Test 23 and the metal can of Test 24 were inferior as cans because film peeling occurred from the end face of the flange portion. Table 2 shows the measurement results of the density of the inner film on the obtained test 23 can and test 24 can. Furthermore, the QTV electrolyte solution was put into the can obtained just under the inner film peeling point, and the QTV test was conducted and the dent resistance was also investigated. The results are shown in Table 2.

As can be seen from Table 2, the cans obtained from Test 23 and Test 24 of Comparative Example 9 were inferior to Examples in terms of soundness of the inner surface film, and were not at a practical level, and the neck processing part was the reaction point of QTV. It was. Further, the dent resistance of the test 23 and the can 24 of the comparative example 9 was inferior to that of the example. As a result, if the film of the can body is not amorphous or close to an amorphous state having a density of 1.360 g / cm ³ or less, film peeling may occur in neck processing and flange processing, and dent resistance will be reduced. It is shown that.

As explained above, the polyester resin film-coated metal plate of the present invention has made it possible to form cans with high speed and high workability, in particular, seamless cans by drawing and ironing. A metal can that is less expensive than the method can be provided.
In addition, since the can obtained from the polyester resin film-coated metal plate of the present invention has excellent soundness of the inner surface film, good corrosion resistance is obtained, and a metal can that can be used with confidence can be provided.

Furthermore, the polyester resin film-covered metal can of the present invention is capable of causing damage or peeling of the inner film at low temperatures or retort even if the can is dropped or otherwise subjected to impact or impact after filling and sealing. Since it becomes difficult to occur even after hot water treatment or hot water treatment such as sterilization treatment or pastro sterilization treatment, it can be filled with various contents, so that a highly versatile metal can can be provided became.


Patent applicant: Nippon Steel Corporation and 1 other
Attorney Attorney Shiina and others 1

Claims (3)

A polyester film-covered metal plate in which a polyester film (F) is coated on the surface corresponding to at least the inner surface side of the can of the metal plate, the polyester film (F) having a thickness of 5 to 20 μm. ) And a polyester film layer (B layer) having a thickness of 5 to 25 μm. The total thickness of the film is 10 to 40 μm. The polyester film layer (B layer) is in contact with the metal plate on the metal plate. The polyester film layer (A layer) has a melting point (A-Tm) of 235 ° C. or higher, an intrinsic viscosity (A-IV) of 0.60 or higher, a heat of crystal melting (A-Hm) and / or cold. 0.5-1.0% by mass of a lubricant having a crystallization heat (A-Hc) of 25-50 J / g, a glass transition temperature (A-Tg) of 65 ° C. or more, and an average particle size of 0.4-2 μm. And heat The Joka agents and / or antioxidants polyester resin (A) as a basic resin containing in the range of 0.01 to 3 parts by weight per 100 parts by weight polyester resin, to further the polyester resin (A) 100 parts by weight From a mixed polyester resin containing 0.1 to 10 parts by mass of fine particles of rubber elastic resin (R) having an equivalent spherical equivalent diameter of 2000 nm or less and 0.01 to 3 parts by mass of a vinyl polymer (V) having a polar group The polyester film layer (B layer) has a melting point (B-Tm) of 220 ° C. or higher, an intrinsic viscosity (B-IV) of 0.55 or higher, a heat of crystal melting (B-Hm) and / or a cold crystal. The heat of formation (B-Hc) is 20 to 45 J / g, the glass transition temperature (B-Tg) is 45 ° C. or more, and the heat stabilizer and / or antioxidant is 0.01 to 100 parts by mass with respect to 100 parts by mass of the polyester resin. 3 parts by mass Polyester resin (B) a basic resin including a range of further polyester resin (B) 5 to 40 parts by weight of fine particles of 2000nm as equivalent spherical converted diameter relative to 100 parts by mass of the rubber elastic resin (R) and a polar group A polyester film-covered metal plate, characterized in that it is a film layer made of a mixed polyester resin containing 1 to 10 parts by mass of a vinyl polymer (V) containing 2. The polyester film-coated metal sheet according to claim 1, wherein the rubber elastic resin (R) is polyethylene and / or ethylene-butene copolymer. The density of the polyester film (F) which is a can obtained by forming from the polyester film-coated metal plate according to claim 1 or 2 and is coated on the inner surface side of the can is 1.360 g. A polyester film-coated metal can characterized by being / cm ³ or less.